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114 results on '"Mirel Birlan"'

1. 2023 DZ2 Planetary Defense Campaign

Author: Vishnu Reddy, Michael S. Kelley, Lance Benner, Jessie Dotson, Nicolas Erasmus, Davide Farnocchia, Tyler Linder, Joseph R. Masiero, Cristina Thomas, James Bauer, Miguel R. Alarcon, Paolo Bacci, Daniel Bamberger, Adam Battle, Zouhair Benkhaldoun, Guido Betti, Mirel Birlan, Marina Brozovic, Brian Burt, David C. Cantillo, Sunil Chandra, Gregoire Chomette, Ashley Coates, Francesca DeMeo, Maxime Devogèle, Petr Fatka, Marin Ferrais, Paolo Fini, Carel van Gend, Jon D. Giorgini, Dmitry Glamazda, Robert Holmes, Joseph L. Hora, Shinji Horiuchi, Kamil Hornoch, Marco Iozzi, Cristóvão Jacques, Emmanuel Jehin, Hai Jiang, Galina Kaiser, Peter Kušnirák, Eduard Kuznetsov, Julia de León, Alexios Liakos, Javier Licandro, Tim Lister, Jing Liu, Andy Lopez-Oquendo, Martina Maestripieri, Donovan Mathias, Marco Micheli, Shantanu P. Naidu, Alessandro Nastasi, Alin Nedelcu, Elisabeta Petrescu, Marcel Popescu, Stephen B. Potter, Petr Pravec, Juan Sanchez, Toni Santana-Ros, Miquel Serra-Ricart, Nick Sioulas, Adrian Sonka, Alessio Squilloni, Maura Tombelli, Madalina Trelia, David E. Trilling, Elizabeth Warner, Guy Wells, Lorien Wheeler, and Mike Wiles
Subjects: Asteroids, Achondrites, Near-Earth objects, Small Solar System bodies, Close encounters, Astronomy, QB1-991
Abstract: We present the results of a fourth planetary defense exercise, focused this time on the small near-Earth asteroid (NEA) 2023 DZ2 and conducted during its close approach to the Earth in 2023 March. The International Asteroid Warning Network (IAWN), with support from NASA's Planetary Defense Coordination Office (PDCO), has been coordinating planetary defense observational campaigns since 2017 to test the operational readiness of the global planetary defense capabilities. The last campaign focused on the NEA Apophis, and an outcome of that exercise was the need for a short burst campaign to replicate a real-life near-Earth object impact hazard scenario. The goal of the 2023 DZ2 campaign was to characterize the small NEA as a potential impactor and exercise the planetary defense system including observations, hypothetical risk assessment and risk prediction, and hazard communication with a short notice of just 24 hr. The entire campaign lasted about 10 days. The campaign team was divided into several working groups based on the characterization method: photometry, spectroscopy, thermal IR photometry and optical polarimetry, radar, and risk assessment. Science results from the campaign show that 2023 DZ2 has a rotation period of 6.2745 ± 0.0030 minutes; visible wavelength color photometry/spectroscopy/polarimetry and near-IR spectroscopy all point to an E-type taxonomic classification with surface composition analogous to aubrite meteorites; and radar observations show that the object has a diameter of 30 ± 10 m, consistent with the high albedo (0.49) derived from polarimetric and thermal IR observations.
Published: 2024
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2. International Asteroid Warning Network Timing Campaign: 2019 XS

Author: Davide Farnocchia, Vishnu Reddy, James M. Bauer, Elizabeth M. Warner, Marco Micheli, Matthew J. Payne, Tony Farnham, Michael S. Kelley, David D. Balam, Anatoly P. Barkov, Daniel Berteşteanu, Mirel Birlan, Bryce T. Bolin, Melissa J. Brucker, Luca Buzzi, Kenneth C. Chambers, Lukas Demetz, Anlaug A. Djupvik, Leonid Elenin, Paolo Fini, Randy Flynn, Gianni Galli, Xing Gao, Marcin Gȩdek, Mikael Granvik, Werner Hasubick, Alexander L. Ivanov, Viktor A. Ivanov, Natalya V. Ivanova, Cristóvão Jaques, Anni Kasikov, Myung-Jin Kim, David Lane, Hee-Jae Lee, Bin Li, Fan Li, Tim Lister, Vadim E. Lysenko, Eugene A. Magnier, Nawaz Mahomed, Jennie McCormick, Darrel Moon, Alessandro Nastasi, Dan A. Nedelcu, Guenther Neue, Elisabeta Petrescu, Marcel Popescu, Enrico Prosperi, Rafał Reszelewski, Dong-Goo Roh, Filipp D. Romanov, Toni Santana-Ros, Anastasia Schmalz, Sergei Schmalz, James V. Scotti, Robert Seaman, Nick Sioulas, Adrian B. Sonka, David J. Tholen, Madalina M. Trelia, Richard Wainscoat, Xin Wang, Guy Wells, Robert Weryk, Nikolai A. Yakovenko, Quanzhi Ye, Hong-Suh Yim, Chengxing Zhai, Chen Zhang, Haibin Zhao, Tinglei Zhu, and Michał Żołnowski
Published: 2022
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3. Single-station meteor detection filtering using machine learning on MOROI data

Author: Simon Anghel, Dan A Nedelcu, Mirel Birlan, and Ioana Boaca
Subjects: Space and Planetary Science, Astronomy and Astrophysics
Abstract: Nowadays, extensive data are collected in an automated regime. Combining this, with the increase in accessible computational power, led to large-scale implementations of machine learning (ML). This is also the case of meteor science, where object detection often requires tracking of a moving light source between frames, and the number of false positives can be up to an order of magnitude higher than true meteoric phenomena. While spatiotemporal coincidence of events recorded by close, multiple cameras can eliminate most of the false positives, single-station detections in some camera networks are currently discarded. In this paper, we explore a set of ML models aiming to find an optimal method for re-analysis of this single-station observations, in order to identify and extract real meteors. A set of 15 ML models were trained on features extracted from the meteor movement. Upon testing, we found a top accuracy score of 98,2 per cent, and a recall (i.e. percentage of meteors correctly classified) score of 96 per cent for the best performing models. When combined with the spatiotemporal coincidence of the detection, the recall increases to 99.92 per cent. These 15 ML techniques were selected according to their ability classify tabular data, hence the bundle can be applied to other studies. The same goes for the computed features, which are independent on the camera configuration, thus, the process can be scaled and applied to other networks. These methods are to be implemented to re-analyze the events recorded by the larger, FRIPON network.
Published: 2022

4. Spectral properties of binary asteroids

Author: Myriam Pajuelo, Mirel Birlan, Benoît Carry, Francesca E DeMeo, Richard P Binzel, and Jérôme Berthier
Published: 2018
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5. Energy signature of ton TNT-class impacts: analysis of the 2018 December 22 fireball over Western Pyrenees

Author: A. Malgoyre, Mar Tapia, D. Rousseu, C. Davadan, S. Jeanne, Detlef Koschny, Theresa Ott, Cyril Blanpain, D. A. Nedelcu, J. Lecubin, Pierre Vernazza, P. Cauhape, Esther Drolshagen, J. Vaubaillon, Brigitte Zanda, Agustín Sánchez-Lavega, Josep M. Trigo-Rodríguez, Mirel Birlan, J. L. Rault, S. Anghel, P. Dupouy, E. Peña-Asensio, M. Herpin, S. J. Ribas, Laurent Jorda, Jérôme Gattacceca, Ricardo Hueso, B. Tregon, Albert Rimola, François Colas, Sylvain Bouley, Ministerio de Ciencia, Innovación y Universidades (España), Diputación Foral de Bizkaia, and Eusko Jaurlaritza
Subjects: Physics, Class (set theory), Meteors, Meteoroid, photometric [Techniques], Astronomy, Astronomy and Astrophysics, Meteoroids, 010502 geochemistry & geophysics, 01 natural sciences, Asteroids: general, Meteorite, Space and Planetary Science, Asteroid, Minor plantes, 0103 physical sciences, Ton, Signature (topology), general [Asteroids], 010303 astronomy & astrophysics, Techniques: photometric, Energy (signal processing), Meteorites, 0105 earth and related environmental sciences
Abstract: Anghel, S., et al., The increase in detector sensitivity and availability in the past three decades has allowed us to derive knowledge of the meteoroid flux and impact energy into the Earth's atmosphere. We present the multi-instrument detected 2018 December 22 fireball over Western Pyrenees, and compare several techniques aiming to obtain a reliable method to be used when measuring impacts of similar scale. From trajectory data alone, we found a bulk density of 3.5 g cm-3 to be the most likely value for the Pyrenean meteoroid. This allowed to further constrain the dynamic mass, which translated into a kinetic energy of 1 ton TNT (4.184 × 109 J). For the second energy derivation, via the fireball's corrected optical radiation, we obtained a more accurate empirical relation measuring well-studied bolides. The result approximates to 1.1 ton TNT, which is notably close to the nominal dynamic result, and agrees with the lower margin of the seismic-based energy estimation, yet way lower than the infrasound estimate. Based on the relation derived in this study, we consider the nominal estimate from both the dynamic and photometric methods to be the most accurate value of deposited energy (1 ton TNT). We show that the combination of these two methods can be used to infer the meteoroid density. Among the methods presented in this paper, we found that the optical energy is the most reliable predictor of impact energy near the ton TNT-scale., S. Anghel and D. A. Nedelcu were supported by a grant of the Romanian Ministry of Research and Innovation, CCCDI - UEFISCDI, project number PN-III-P1-1.2-PCCDI-2017-0226/16PCCDI/2018, within PNCDI III. EP-A and JMT-R acknowledge funding from PGC2018-097374-B-I00 (MCI-AEI-FEDER, EU). M. Birlan work was partly supported by SEEING-IEA CNRS program. R. Hueso and A. Sánchez-Lavega were supported by Diputación Foral de Bizkaia and Gobierto Vasco IT1366-19.
Published: 2021

6. Constraining the shape and density of binary asteroid (121) Hermione

Author: Marin Ferrais, Pierre Vernazza, Michaël Marsset, Laurent Jorda, Benoit Carry, Josef Hanus, Miroslav Brož, Bin Yang, Romain Fétick, Franck Marchis, Frederic Vachier, Mirel Birlan, Emmanuël Jehin, Edyta Podlewska-Gaca, Przemyslaw Bartczak, Thierry Fusco, and Grzegorz Dudziński
Abstract: Context (121) Hermione is a large binary asteroid [1] located at the outer edge of the asteroid belt in the Cybele region, where asteroids are thought to be linked to the outer Solar System. Hermione has a Ch/Cgh-type that has been linked to CM chondrites. Adaptive optics observations between 2003 and 2008 suggest a rare bilobate shape for the primary [2,3]. However, Hermione’s shape and bulk density (ranging between 1.4 and 2 g.cm-3) remain poorly constrained to this day. Aim We acquired spatially resolved images and optical lightcurves of Hermione during its close apparition of September 2021. It was the best chance in 13 years to acquire such high angular resolution images (angular diameter = 0.14”). We aimed to constrain Hermione’s 3D shape, hence its volume, and the orbit of its satellite, hence the mass of the system. Combining the volume and the mass allows to constrain the bulk density with high accuracy. Methods We obtained 8 series of 5 images with the SPHERE/ZIMPOL instrument on the Very Large Telescope (ESO Program ID 107.22UT.001; PI: P. Vernazza). These images were combined with optical lightcurves and stellar occultations by the ADAM and MPCD methods [4,5] to reconstruct the asteroid’s 3D shape. For the determination of the satellite’s orbit, we complemented the SPHERE images with a compilation of archival data from other large ground-based AO instruments (KeckII/NIRC2, ESO/VLT/NACO and Gemini-North/NIRI). Then, we used the meta-heuristic algorithm Genoid [6] to accurately determine the orbital elements. Results The determined volume and mass of Hermione yield a new higher bulk density of ~1.7 g.cm-3, more compatible with its Ch/Cgh classification. We will also present our analyse of the shape and compare it with other elongated Ch/Cgh asteroids. Bibliography [1] Merline et al. (2002), IAU Circ. 7980 [2] Marchis et al. (2005), Icarus, 178, 2, p. 450-464 [3] Descamps et al. (2009), Icarus, 203, 1, p. 88-101 [4] Viikinkoski, M., Kaasalainen, M., & Durech, J. (2015), A&A, 576, A8 [5] Capanna, C., Gesquière, G., Jorda, L., Lamy, P., & Vibert, D. (2013), The Visual Computer, 29, 825 [6] Vachier, F., Berthier, J. and Marchis, F. (2012), A&1, 543, A68
Published: 2022

7. Machine learning methods applied to meteor detection filtering

Author: Simon Anghel, Dan-Alin Nedelcu, Mirel Birlan, and Ioana Boaca
Abstract: Introduction: Recent expansions in fireball networks has lead to an increase in the number of events recorded each night. Due to the mechanism at the source of the detection procedure (i.e. tracking sources of light), the majority of the events is comprised of false meteors. These make their way in trajectory computations, and lead to erroneous orbits [e.g. 1]. Aims: For this study we explore several machine learning (ML) models for their ability to filter the false detections. Methods: First, a supervised validation was employed on the meteor detections obtained by stations within the Meteorites Orbits Reconstruction by Optical Imaging (MOROI) network [1, 2], between 2017-2020. Next, a set of ML models suited for classification were applied to a selection of features computed from the data. Finally, each model was tuned to their optimal hyper-parameter value, to obtain the highest score. Results: The Neural networks method was found to best filter out the false meteors, with a recall score of 96%, followed by 95% for Gradient Boost and Random Forest algorithms. The score is expected to increase when employing a spatio-temporal filter and pixel brightness information. The results entail follow-up studies on the currently expanding FRIPON network [4]. References: [1] Gural et al. (2020) Planetary and Space Science 182, 104847. [2] Nedelcu D. A. et al. (2018) Romanian Astronomical Journal 28, 1, 3-11. [3] Anghel S. et al. (2021) in LPI Contributions 84, Abstract #6027. [3] Colas F. et al. (2020) Astronomy & Astrophysics 644:A53.
Published: 2022

8. Analysis of the meteorite-producing fireballs registered by the MOROI component of the FRIPON network

Author: Ioana Lucia Boaca, Jarmo Moilanen, Maria Gritsevich, Mirel Birlan, Alin Nedelcu, Tudor Boaca, François Colas, Adrien Malgoyre, Brigitte Zanda, Pierre Vernazza, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut Pythéas (OSU PYTHEAS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire d'Astrophysique de Marseille (LAM), and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDU]Sciences of the Universe [physics]
Abstract: 1. IntroductionThe Fireball Recovery and Inter Planetary Observation Network (FRIPON) network [1] uses all-sky cameras in order to detect fireballs. The FRIPON network comprises over 150 cameras installed all over Europe [1]. In this work we focus on the results obtained by the Meteorite Orbits Reconstruction by Optical Imaging (MOROI) [2] component of the FRIPON network in Romania. As of May 2022, the MOROI network detects the events with the use of 13 all-sky cameras.2. MethodsThe method for computing the fireball trajectory used by FRIPON is presented in [3].The height, velocity and slope γ of the meteoroid are the input data for computing the ballistic coefficient α and the mass-loss parameter β. We select the candidates that are likely to produce meteorites of the ground using the α-β algorithm presented in [4], [5], [6], [7]. 3. Results Starting from January 2021 (the starting moment of data fusion of the MOROI network into the FRIPON network) until the present time (May 2022) over 100 meteors were detected. We present the most spectacular events that are likely to result on a meteorite production on the surface of the Earth. Figure 1: The outcome of the FRIPON (MOROI) detections in Romania In Figure 1 are represented the coordinates of the meteoroids with noticeable deceleration in the (ln(αsinγ),lnβ) coordinates system. The values of the shape parameter correspond to the cases when the meteoroid doesn’t rotate (µ=0) or rotates uniformly (µ=2/3). The boundaries (‘likely fall’, ‘possible fall’, ‘unlikely fall’) are represented for meteoroids with final mass of 50 g. We processed the 100 detections of the FRIPON (MOROI) network in Romania. From this amount of data, we found 15 fireball events with noticeable deceleration. We found one event in the ‘likely fall’ area and three events in the ‘possible fall’ area. The fireball that is likely to produce meteorites was detected by the MOROI network on 24.11.2021 at 19:20:57 UT. We model the dark flight trajectory of the meteoroids with the ‘likely fall’ and ‘possible fall’ outcomes and determine their strewn field with the model presented in [8], [9]. We use the wind model from the European Centre for Medium-Range Weather Forecasts (ECMWF). A meteorite recovery campaign will be organised to identify the strewn field area. Acknowledgement. The work of IB and MB was partially supported by a grant of the Romanian Ministry of Education and Research, CNCS-UEFISCDI, project number PN-III-P1-1.1-PD-2019-0784, within PNCDI III. The work of IB, MB, AN was partially supported by a grant of the Ministry of National Education and Scientific Research, PNIII-P2-1214/25.10.2021, program no. 36SOL/2021. JM and MG acknowledge the Academy of Finland project no. 325806 (PlanetS). References: [1] Colas F., Zanda B., Bouley S., Jeanne S., Malgoyre A., Birlan M., Blanpain C., Gattacceca J., Jorda L., Lecubin J., et al. (385 more) FRIPON: a worldwide network to track incoming meteoroids. Astronomy &. Astrophys. 644, A53. doi:10.1051/0004-6361/202038649. 2020. [2] Nedelcu D.A., Birlan M., Turcu V., Boaca I., Badescu O., Gornea A., Sonka A.B., Blagoi O., Danescu C., Paraschiv P. Meteorites Orbits Reconstruction by Optical Imaging (MOROI) Network. Romanian Astronomical Journal 28(1), 57 – 65. 2018. [3] Jeanne, S., Colas, F., Zanda, B., Birlan, M., Vaubaillon, J., Bouley, S., Vernazza, P., Jorda, L., Gattacceca, J., Rault, J. L., Carbognani, A., Gardiol, D., Lamy, H., Baratoux, D., Blanpain, C., Malgoyre, A., Lecubin, J., Marmo, C., Hewins, P. Calibration of fish-eye lens and error estimation on fireball trajectories: application to the FRIPON network. Astronomy and Astrophysics, 627:A78. 2019. [4] Gritsevich, M. I. The Pribram, Lost City, Innisfree, and Neuschwanstein falls: An analysis of the atmospheric trajectories. Solar System Research.42, 372–390. 2008. [5] Gritsevich, M.I., Stulov, V.P., Turchak, L.I. Consequences of collisions of natural cosmic bodies with the Earth's atmosphere and surface. Cosmic Research vol.50, no.1, 56-64. 2012. [6] Sansom, E.K., Gritsevich, M., Devillepoix, H.A.R., Jansen-Sturgeon, T., Shober, P., Bland, P.A., Towner, M.C., Cupák, M., Howie, R.M., Hartig, B.A.D. Determining Fireball Fates Using the α-β Criterion. Astrophysical Journal 885(2):115. 2019. [7] Boaca I., Gritsevich M., Birlan M., Nedelcu, A., Boaca, T., Colas, F., Malgoyre, A., Zanda, B., Vernazza P., to be submitted. 2022. [8] Moilanen, J., Gritsevich, M., Lyytinen, E., Determination of strewn fields for meteorite falls, Monthly Notices of the Royal Astronomical Society 503, 3337–3350. 2021. [9] Boaca I., Nedelcu A., Birlan M., Boaca T., Anghel S. Mathematical model for the dark-flight trajectory of a meteoroid, Romanian Astronomical Journal, Vol. 31, No. 2. 2021.
Published: 2022

9. Colours and taxonomy of 2022 AB: a super fast rotating near-Earth asteroid

Author: Paweł Koleńczuk, Tomasz Kwiatkowski, Monika Kamińska, Krzysztof Kamiński, Francois Colas, Alain Klotz, Taewoo Kim, and Mirel Birlan
Abstract: Introduction 2022 AB is a very small near-Earth asteroid that passed Earth at a distance of 9.6 lunar distances on 20 January. Our campaign started on 4 January and until 26 January, we observed 2022 AB using telescopes located in many places around the world. More about the campaign, including the determination of the phase curve, will be presented during this conference in a separate presentation [2]. Here we only present results regarding the colour indices, taxonomic class, and diameter. We organised a similar observation campaign for 2021 DW1 in 2021 [3][4][5]. Rotation period In determining the colours indices, it is very important to know the rotation period of the asteroid. We discussed the issues, especially in the field of NEAs, at the conference last year [5]. We briefly discuss the determination of the rotation period using an example of observations from the first night of the campaign of 2022 AB. More will be discussed in [2]. We used a 0.7-m RBT/PST2 telescope(Arizona), 5-s exposures, and the clear filter. We observed object for 1.5 hours and we create composite lightcurve with Fourier series fit (see Figure 1). In this way, we determined the rotation period P=182 s. Figure 1: Example of composite lightcurve of 2022 AB. Colour indices The preliminary results presented here are based on most of the data obtained. The full results will be presented during the conference. To determine the colour indices, we used observations from three telescopes: 0.7-m RBT, 1-m telescope of DOAO (South Korea), and 1-m telescope of Pic du Midi Observatory (France). Telescopes from DOAO and Pic du Midi observed the asteroid with an exposure time of several seconds in the B,V,R,I (DOAO) or g’,r’,i’,z’ (Pic du Midi) filters. Due to changes in the geometry of the observations, we divided the observations into several sets. Using solar analogues, we transformed the brightness in B,V,R,I into g’,r’,i’,z’ bands, respectively. Then, knowing the rotation period, we composited the lightcurves to determine the shifts between the lightcurves in the given bands. We have prepared the composited lightcurves separately for each set. An example is shown in Figure 2. RBT observations were made in B,V,R filters and, as we mentioned, transformed them into g’,r’,i’. In this case, we used knowledge of the rotation period to average the brightness measurements over the period, exposure time Texp=P=182s. Adjacent measurements in different bands allowed us to determine a series of colour indices that we averaged as one set. The results for each set are shown in Table 1. Figure 2: Composite lightcurves for DOAO set 1. Top: lightcurves in i’ (dots) and z’ band (crosses), middle: i’ and (dots) and r’ (crosses) bands, bottom: r’ (dots) and g’ (cross) bands. Table 1: Preliminary results of colour indices for each set. Taxonomy To determine the taxonomic class of 2022 AB, we converted the average value of colour indices to the reflection coefficients Rr,Ri and Rz, normalised to the reflection values in the g band, using the formula [6]: Rf=10−0.4[(f−g)−(f☉−g☉)] Next, we compared them with spectra of different taxonomic classes, as given by [6]. In Figure 3 we present the reflective value of the asteroid compared to similar taxonomic classes. B class asteroids are rare and they are mainly associated with the outer main belt. 2022 AB as an NEA is an unlikely class B asteroid. The Cb class fits well with the data of 2022 AB and is the only one to show the common with 2022 AB characteristic of visible absorption around 0.6 micrometre. We suggest that 2022 AB is most likely a type Cb asteroid. Figure 3: Plot of reflectivities values of B,Cb,Ch asteroid classes (black dots) and 2022 AB (red dots). Data for the B,Cb, and Ch classes were taken from [6]. Diameter We can determine the diameter knowing the absolute magnitude H and the albedo pV according to equation [7]: Deff=1329×10−H/5×pV−0.5 At the conference, we will present the results based on the determined H from the phase curve, but for now we used the approximate H=23.6±0.36 given by JPL[1]. Albedo for Cb class asteroids: pV=0.059±0.027 [8], hence Deff=0.104±0.029 km. Figure 4: Rotation period-diameter plot. The red dotted line is the spin barrier (2.2 h). Other asteroid data come from LCDB [8]. Acknowledgements This research was funded in whole or in part by the National Science Centre, Poland, grant No. 2021/41/N/ST9/04259. References [1] https://ssd.jpl.nasa.gov[2] Kwiatkowski et al. (2022) Photometry and model of near-Earth asteroid 2022 AB from one apparition,EPSC 2022, held 18–23 September 2022 in Granada, Spain[3] Kwiatkowski et al. (2021) A&A 656, A126[4] Kwiatkowski et al. (2021) Photometry and model of near-Earth asteroid 2021 DW1 from one apparition, EPSC 2021, held virtually, 13-24 September 2021[5] Koleńczuk et al. (2021) Determination of colour indices of super-fast rotator near-Earth asteroids, EPSC 2021, held virtually, 13-24 September 2021[6] DeMeo & Carry (2013), Icarus 226, 723[7] Fowler and Chillemi (1992) Phillips Laboratory, Hanscom AF Base, MA, 17–43[8] Warner et al. (2009) Icarus 202, 134
Published: 2022

10. The interaction of meteoroids with the atmosphere

Author: Ioana Lucia Boaca, Maria Gritsevich, Mirel Birlan, Alin Nedelcu, and Tudor Boaca
Abstract: In this work we present the main results of the project named ‘Meteor mathematical modelling of dark flight’ (MeMATH), and current state and future work related to our project. The MeMATH project started in September 2020.The main objectives of the MeMATH project are:i) numerical simulation of the dark-flight trajectory;ii) determining the search area for meteorite fragments;iii) the study of the ablation of large bodies.In the first stage of the project, we developed a mathematical model for the dark flight trajectory of a meteoroid. The novelty of our model is that it considers the ellipsoidal shape of the Earth, the Coriolis effect and the centrifugal force.In the current stage of the project, we are determining the ballistic coefficient α and the mass loss parameter β based on the meteoroid height and deceleration.The α and β parameters have a great impact in the study of meteoroids from the identification of the parent body to determining the initial and final mass and finding out weather the remnant matter after ablation could result in a meteorite on the ground.Acknowledgement.The work of IB and MB was supported by a grant of the Romanian Ministry of Education and Research, CNCS-UEFISCDI, project number PN-III-P1-1.1-PD-2019-0784, within PNCDI III.
Published: 2022

11. Cloud coverage estimation via deep learning applied to all-sky data in Romania : First Results

Author: Simon Anghel, Mirela Voiculescu, Dan-Alin Nedelcu, and Mirel Birlan
Abstract: Measuring the level of cloud coverage (CC) is important when analysing the absorption of solar radiation, the cloud formation process, and also to improve the forecast in general. This is becoming a more common task with the availability of digital sensors and their usage in monitoring the sky.In this study we present a method of estimating the level of cloud coverage using Deep Learning (DL) applied to all-sky images of Meteorites Orbits Reconstruction by Optical Imaging (MOROI) network.To label the data, a supervised validation was employed on the daytime images captured during the course of two years, recorded on Galati, Romania These were divided into three groups; CC 80%. Next, a set of DL models were trained, optimized and tested towards accurately classifying images according to each group.We found that the classification accuracy can range between 89-95 % depending on how the cloud coverage is labeled and how the daytime is defined. This is mostly due to thin cirrus clouds, tricking the models, or poor sky illumination during sunrise or sunset. We discuss these methods and present a few strategies which circumvent classification problems, to further increase the accuracy of models.The next step is to extend the study on the rest of the network, and also combining it with other sensors (e.g. satellite data) in order to understand the cloud-circulation coupling and its impact across climate models.
Published: 2022

12. Characterization of the Fireballs Detected by All-sky Cameras in Romania

Author: Ioana Boaca, Maria Gritsevich, Mirel Birlan, Alin Nedelcu, Tudor Boaca, François Colas, Adrien Malgoyre, Brigitte Zanda, Pierre Vernazza, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut Pythéas (OSU PYTHEAS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Department of Physics, Planetary-system research, Faculty of Science, Maanmittauslaitos, and National Land Survey of Finland
Subjects: Motion, Meteors, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Space and Planetary Science, [SDU]Sciences of the Universe [physics], Meteorite, Astronomy and Astrophysics, Meteoroids, 115 Astronomy, Space science, 114 Physical sciences, Meteorites
Abstract: Some of the fields of research that have captured the persistent interest of both scientists and the general public are meteor phenomena. The main goal in the study of meteoroid impacts into Earth’s atmosphere is the recovery of the remnant matter after the ablation in the form of meteorites. This is a complementary approach, yet cheap alternative, to a sample return mission. Meteoroids are messengers since the time of the formation of the solar system due to the fact that they have preserved the same composition. The study of meteorites provides information regarding the chemical composition from which the planets formed. The increasing number of all-sky camera networks in recent years has resulted in a large set of events available for study. Thus, it is very important to use a method that determines whether the meteoroid could produce a meteorite or not. In this paper we study the meteors detected by the FRIPON network in Romania with the use of all-sky cameras. We focus on the events with noticeable deceleration (V f /V 0 < 0.8). We determine the ballistic coefficient α and the mass-loss parameter β for the selected sample. Based on this analysis the events are classified in three categories: (1) meteoroids that are likely to produce meteorites; (2) meteoroids that can possibly produce meteorites; (3) meteoroids that are unlikely to produce meteorites. The entry and final mass are determined for each event. From the recorded fireballs, we identified one possible meteorite dropper, and we analyzed its dynamical evolution.
Published: 2022

13. Active Asteroid (6478) Gault: A Blue Q-type Surface below the Dust?

Author: Michaël Marsset, Francesca DeMeo, Adrian Sonka, Mirel Birlan, David Polishook, Brian Burt, Richard P. Binzel, Shelte J. Bus, and Cristina Thomas
Published: 2019
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14. Photometric survey of 55 near-earth asteroids

Author: F. Colas, M. Fulchignoni, Mirel Birlan, E. Dotto, E. Petrescu, D. Perna, A. Sonka, S. Fornasier, T. Hromakina, M. A. Barucci, F. Merlin, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Agroécologie [Dijon], Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Observatorul Astronomic 'Amiral Vasile Urseanu' [Bucharest], Astronomical Observatory 'Admiral Vasile Urseanu', Bucharest Municipal Museum, the NEOROCKS Team, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Near-Earth object, 010504 meteorology & atmospheric sciences, Astronomy, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, asteroids: general, [SHS.HISPHILSO]Humanities and Social Sciences/History, Philosophy and Sociology of Sciences, techniques: photometric, surveys, Space and Planetary Science, 0103 physical sciences, minor planets, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: Context. Near-earth objects (NEOs), thanks to their proximity, provide a unique opportunity to investigate asteroids with diameters down to dozens of meters. The study of NEOs is also important because of their potential hazard to the Earth. The investigation of small NEOs is challenging from Earth as they are observable only for a short time following their discovery and can sometimes only be reached again years or decades later. Aims. We aim to derive the visible colors of NEOs and perform an initial taxonomic classification with a main focus on smaller objects and recent discoveries. Methods. Photometric observations were performed using the 1.2 m telescope at the Haute-Provence observatory and the 1.0 m telescope at the Pic du Midi observatory in broadband Johnson-Cousins and Sloan photometric systems. Results. We present new photometric observations for 55 NEOs. Our taxonomic classification shows that almost half (43%) of the objects in our sample are classified as S+Q-complex members, 19% as X-complex, 16% as C-complex, 12% as D-types, and finally 6% and 4% as A- and V-types, respectively. The distribution of the observed objects with H > 19 and H ≤ 19 remains almost the same. However, the majority of the objects in our dataset with D < 500 m belong to the “silicate” group, which is probably a result of an observational bias towards brighter and more accessible objects. “Carbonaceous” objects are predominant among those with a Jovian Tisserand parameter of Tj < 3. These bodies could be dormant or extinct comets. The median values of the absolute magnitude for “carbonaceous” and “silicate” groups are H = 18.10 ± 0.95 and H = 19.50 ± 1.20, whereas the estimated median diameters are D = 1219 ± 729 m and D = 344 ± 226 m, respectively. “Silicate” objects have a much lower median Earth’s minimum orbit intersection distance (MOID) and a somewhat lower orbital inclination in comparison to “carbonaceous” objects. About half of the observed objects are potentially hazardous asteroids and are mostly (almost 65%) represented by “silicate” objects.
Published: 2021

15. VLT/SPHERE imaging survey of the largest main-belt asteroids: Final results and synthesis

Author: J. Krajewski, P. Aurard, Philippe Lamy, Vishnu Reddy, Laurent Jorda, D. Molina, Josef Hanus, Josef Ďurech, P. Michel, F. Vachier, Nicolas Rambaux, J. Oey, Grzegorz Dudziński, P. Bartczak, A. Leroy, Michael Marsset, L. Dalmon, P. Beck, H. Le Coroller, Hiroko Hamanowa, Maëlle Neveu, Christophe Dumas, Hiromi Hamanowa, A. G. Sanchez, Zouhair Benkhaldoun, N. Payre, E. Podlewska-Gaca, Fabrice Cipriani, Raoul Behrend, Paolo Tanga, Aled Jones, Julie Castillo-Rogez, Miroslav Brož, P. Antonini, Tadeusz Michalowski, F. Livet, O. Labrevoir, J. M. Bosch, Emmanuel Jehin, Arthur Vigan, S. Fauvaud, A. Chapman, Marin Ferrais, Jérôme Berthier, Alexis Drouard, Mirel Birlan, J. Grice, R. Montaigut, J. His, L. Socha, Romain Fétick, Olivier Witasse, Pierre Vernazza, Thierry Fusco, Benoit Carry, F. Marchis, Doeon Kim, Toni Santana-Ros, Mikko Kaasalainen, Matti Viikinkoski, P. Sabin, M. Audejean, A. Marciniak, Myung-Jin Kim, Bin Yang, Agnieszka Kryszczyńska, François Colas, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institute of Astronomy [Prague], Charles University [Prague] (CU), Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS, Laboratoire Lagrange, Nice, France, Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), Tampere University of Technology [Tampere] (TUT), Search for Extraterrestrial Intelligence Institute (SETI), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Astronomical Institute of Romanian Academy, Romanian Academy, Adam Mickiewicz University in Poznań (UAM), Institut de Recherche en Horticulture et Semences (IRHS), Université d'Angers (UA)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université de Liège, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), California Institute of Technology (CALTECH), European Space Agency (ESA), TMT Observatory, The Open University [Milton Keynes] (OU), Department of Mathematics [Tampere], University of Maryland [College Park], University of Maryland System, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Hospices Civils de Lyon (HCL), Research on Healthcare Performance (RESHAPE - Inserm U1290 - UCBL1), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Santé et de la Recherche Médicale (INSERM), Universidad de Alicante, Universitat de Barcelona (UB), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Observatoire de Chinon, Institut Pythéas (OSU PYTHEAS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Observatoire de Haute-Provence (OHP), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Geneva Observatory, University of Geneva [Switzerland], Université Cadi Ayyad [Marrakech] (UCA), Héritages et Constructions dans le Texte et l'Image (HCTI), Institut Brestois des Sciences de l'Homme et de la Société (IBSHS), Université de Brest (UBO)-Université de Brest (UBO)-Université de Bretagne Sud (UBS)-Université de Brest (UBO), Observatoire du Bois de Bardon, Association T60, Observatoire Midi-Pyrénées, Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Laboratory for Space Research [Hong Kong] (LSR), The University of Hong Kong (HKU), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Korea Astronomy and Space Science Institute (KASI), Okayama University, Chungbuk National University, Laboratoire d'analyse et de recherche en économie et finance internationales (Larefi), Université de Bordeaux (UB), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Anunaki Observatory, Sanofi-Aventis R&D, SANOFI Recherche, Planetary Science Institute [Tucson] (PSI), Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Ministerio de Economía y Competitividad (España), Belgian Science Policy Office, National Science Foundation (US), Generalitat Valenciana, Université Côte d'Azur (UCA), Université d'Angers (UA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-INSTITUT AGRO Agrocampus Ouest, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Agence Spatiale Européenne = European Space Agency (ESA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université de Genève = University of Geneva (UNIGE), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Brestois des Sciences de l'Homme et de la Société (IBSHS), Université de Brest (UBO), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Tampere University, and Computing Sciences
Subjects: asteroids, Rotation period, Surface (mathematics), Shell (structure), [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], general [Minor planets, asteroids], Context (language use), Astrophysics, 01 natural sciences, 03 medical and health sciences, Física Aplicada, 0103 physical sciences, 111 Mathematics, observational [Methods], 010303 astronomy & astrophysics, 030304 developmental biology, Physics, Asteroids:general, 0303 health sciences, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Minor planets, techniques: high angular resolution, Astronomy and Astrophysics, 113 Computer and information sciences, asteroids: general, Bimodality, high angular resolution [Techniques], Density distribution, 115 Astronomy and space science, Space and Planetary Science, Asteroid, [SDU]Sciences of the Universe [physics], minor planets, methods: observational, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], general [Asteroids], high angular resolution, Shape analysis (digital geometry)
Abstract: Vernazza, P., et al., Until recently, the 3D shape, and therefore density (when combining the volume estimate with available mass estimates), and surface topography of the vast majority of the largest (D ≥ 100 km) main-belt asteroids have remained poorly constrained. The improved capabilities of the SPHERE/ZIMPOL instrument have opened new doors into ground-based asteroid exploration. Aims. To constrain the formation and evolution of a representative sample of large asteroids, we conducted a high-angular-resolution imaging survey of 42 large main-belt asteroids with VLT/SPHERE/ZIMPOL. Our asteroid sample comprises 39 bodies with D ≥ 100 km and in particular most D ≥ 200 km main-belt asteroids (20/23). Furthermore, it nicely reflects the compositional diversity present in the main belt as the sampled bodies belong to the following taxonomic classes: A, B, C, Ch/Cgh, E/M/X, K, P/T, S, and V. Methods. The SPHERE/ZIMPOL images were first used to reconstruct the 3D shape of all targets with both the ADAM and MPCD reconstruction methods.We subsequently performed a detailed shape analysis and constrained the density of each target using available mass estimates including our own mass estimates in the case of multiple systems. Results. The analysis of the reconstructed shapes allowed us to identify two families of objects as a function of their diameters, namely spherical and elongated bodies. A difference in rotation period appears to be the main origin of this bimodality. In addition, all but one object (216 Kleopatra) are located along the Maclaurin sequence with large volatile-rich bodies being the closest to the latter. Our results further reveal that the primaries of most multiple systems possess a rotation period of shorter than 6 h and an elongated shape (c=a ≤ 0.65). Densities in our sample range from ∼1.3 g cm-3 (87 Sylvia) to ∼4.3 g cm-3 (22 Kalliope). Furthermore, the density distribution appears to be strongly bimodal with volatile-poor (P ≥ 2.7 g cm-3) and volatile-rich (P ≤ 2.2 g cm-3) bodies. Finally, our survey along with previous observations provides evidence in support of the possibility that some C-complex bodies could be intrinsically related to IDP-like P- and D-type asteroids, representing different layers of a same body (C: core; P/D: outer shell). We therefore propose that P/ D-types and some C-types may have the same origin in the primordial trans-Neptunian disk., We warmly thank the ESO staff at Paranal and in particular Henri Boffin for providing us precious support and advice throughout the entire observing programme. P.V., A.D., M.F., L.J. and B.C. were supported by CNRS/INSU/PNP. The work of T.S-R. was carried out through grant APOSTD/2019/046 by Generalitat Valenciana (Spain). This work was supported by the MINECO (Spanish Ministry of Economy) through grant RTI2018-095076-B-C21 (MINECO/FEDER, UE). TRAPPIST project is funded by the Belgian Fund for Scientic Research (Fond National de la Recherche Scientique, FNRS) under the grant PDR T.0120.21. E.J. is a FNRS Senior Research Associate. F.M. is supported by the National Science Foundation under Grant No. 1743015.
Published: 2021

16. An advanced multipole model for (216) Kleopatra triple system

Author: Laurent Jorda, Josef Hanus, François Colas, Alexis Drouard, J. Grice, Julie Castillo-Rogez, Patrick Michel, Philippe Lamy, Pierre Vernazza, Josef Ďurech, Miroslav Brož, Bin Yang, Matti Viikinkoski, Franck Marchis, Tadeusz Michalowski, Marin Ferrais, Fabrice Cipriani, Thierry Fusco, Nicolas Rambaux, Olivier Witasse, Przemyslaw Bartczak, Arthur Vigan, David Vokrouhlický, Emmanuel Jehin, E. Podlewska-Gaca, Toni Santana-Ros, Frédéric Vachier, M. Pajuelo, Paolo Tanga, S. Benseguane, Romain Fétick, Christophe Dumas, Grzegorz Dudziński, Mirel Birlan, Agnieszka Kryszczyńska, S. Fauvaud, Anna Marciniak, Benoit Carry, J. Berthier, Michael Marsset, Institute of Astronomy [Prague], Charles University [Prague] (CU), Search for Extraterrestrial Intelligence Institute (SETI), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), Tampere University of Technology [Tampere] (TUT), Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Space Sciences, Technologies and Astrophysics Research Institute (STAR), Université de Liège, SETI Institute, Ondřejov Observatory of the Prague Astronomical Institute, Czech Academy of Sciences [Prague] (CAS), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire du Bois de Bardon, Astronomical Institute of Romanian Academy, Romanian Academy, Thirty Meter Telescope Observatory, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), DOTA, ONERA, Université Paris Saclay [Châtillon], ONERA-Université Paris-Saclay, School of Physical Sciences [Milton Keynes], Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Pontificia Universidad Católica del Perú = Pontifical Catholic University of Peru (PUCP), Universidad de Alicante, Institut de Ciencies del Cosmos (ICCUB), Universitat de Barcelona (UB), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Czech Science Foundation, Charles University (Czech Republic), National Science Foundation (US), National Aeronautics and Space Administration (US), Generalitat Valenciana, Ministerio de Ciencia, Innovación y Universidades (España), Fédération Wallonie-Bruxelles, and Belgian Science Policy Office
Subjects: 010504 meteorology & atmospheric sciences, fundamental parameters [Planets and satellites], Library science, FOS: Physical sciences, Astrophysics, 01 natural sciences, methods: numerical, Física Aplicada, 0103 physical sciences, Celestial mechanics, planets and satellites: fundamental parameters, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), [PHYS]Physics [physics], numerical [Methods], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Minor planets, Astronomy and Astrophysics, Astrometry, celestial mechanics, asteroids: individual: (216) Kleopatra, individual: (216) Kleopatra [Asteroids], Space and Planetary Science, individual: (216) Kleopatra [Minor planets, asteroids], minor planets, astrometry, TRAPPIST, Christian ministry, Earth and Planetary Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract: [Aims] To interpret adaptive-optics observations of (216) Kleopatra, we need to describe an evolution of multiple moons orbiting an extremely irregular body and include their mutual interactions. Such orbits are generally non-Keplerian and orbital elements are not constants. [Methods] Consequently, we used a modified N-body integrator, which was significantly extended to include the multipole expansion of the gravitational field up to the order ℓ = 10. Its convergence was verified against the 'brute-force' algorithm. We computed the coefficients Cℓ m, Sℓ m for Kleopatra's shape, assuming a constant bulk density. For Solar System applications, it was also necessary to implement a variable distance and geometry of observations. Our χ2 metric then accounts for the absolute astrometry, the relative astrometry (second moon with respect to the first), angular velocities, and silhouettes, constraining the pole orientation. This allowed us to derive the orbital elements of Kleopatra's two moons. [Results] Using both archival astrometric data and new VLT/SPHERE observations (ESO LP 199.C-0074), we were able to identify the true periods of the moons, P1 = (1.822359 ± 0.004156) d, P2 = (2.745820 ± 0.004820) d. They orbit very close to the 3:2 mean-motion resonance, but their osculating eccentricities are too small compared to other perturbations (multipole, mutual), meaning that regular librations of the critical argument are not present. The resulting mass of Kleopatra, m1 = (1.49 ± 0.16) × 10-12 M· or 2.97 × 1018 kg, is significantly lower than previously thought. An implication explained in the accompanying paper is that (216) Kleopatra is a critically rotating body., Broz, M. et al., This work has been supported by the Czech Science Foundation through grant 21-11058S (M. Brož, D. Vokrouhlický), 20-08218S (J. Hanuš, J. Ďurech), and by the Charles University Research program No. UNCE/SCI/023. This material is partially based upon work supported by the National Science Foundation under Grant No. 1743015. P.V., A.D., M.F. and B.C. were supported by CNRS/INSU/PNP. M.M. was supported by the National Aeronautics and Space Administration under grant No. 80NSSC18K0849 issued through the Planetary Astronomy Program. The work of TSR was carried out through grant APOSTD/2019/046 by Generalitat Valenciana (Spain). This work was supported by the MINECO (Spanish Ministry of Economy) through grant RTI2018-095076-B-C21 (MINECO/FEDER, UE). The research leading to these results has received funding from the ARC grant for Concerted Research Actions, financed by the Wallonia-Brussels Federation. TRAPPIST is a project funded by the Belgian Fonds (National) de la Recherche Scientifique (F.R.S.-FNRS) under grant FRFC 2.5.594.09.F. TRAPPIST-North is a project funded by the University of Liège, and performed in collaboration with Cadi Ayyad University of Marrakesh. E. Jehin is a FNRS Senior Research Associate.
Published: 2021

17. Trajectory and dark-flight estimation for meteoroids detected by the MOROI network

Author: Ioana Lucia Boaca, Alin Nedelcu, Mirel Birlan, Tudor Boaca, and Simon Anghel
Abstract: The Romanian all-sky network Meteorites Orbits Reconstruction by Optical Imaging (MOROI) was deployed in 2017 [3] and it is fully compatible with the FRIPON one [2]. In 2020 we started to integrate the MOROI database into the FRIPON one. Figure 1 presents the statistics of the weekly multiple events (detected by two or more cameras) for 2017-2019. Figure 2 presents the preliminary statistics of number of meteors vs. duration of luminous phenomenon for 2017-2020. Nowadays the MOROI network consists of 16 all-sky cameras (to be extended to 24). In [1] is presented a mathematical model for the dark-flight trajectory of a meteoroid based on the influence of the wind, the properties of the atmosphere, the Coriolis force and the centrifugal force. This model uses the ellipsoid shape of the Earth instead of the classical spherical one and a stochastic analysis of meteoroids inside a range of velocities using a Gaussian distribution. In this paper we present some of the detections from the MOROI network. We present their luminous trajectory and we apply the dark-flight model from [1] in order to obtain their strewn field. Figure 1: Number of weekly events for 2017-2019 Figure 2: Distribution of duration of meteors for 2017-2020 Acknowledgements: This work was supported by a grant of the Romanian Ministry of Education and Research, CNCS-UEFISCDI, project number PN-III-P1-1.1-PD-2019-0784, within PNCDI III. References: [1] Boaca I., Nedelcu A., Birlan M., Boaca T., Anghel S. Mathematical model for the dark-flight trajectory of a meteoroid, submitted to Romanian Astronomical Journal. [2] Colas F., Zanda B., Bouley S., Jeanne S., Malgoyre A., Birlan M., Blanpain C., Gattacceca J., Jorda L., Lecubin J., et al. (385 more) FRIPON: a worldwide network to track incoming meteoroids. Astronomy &. Astrophys. 644, A53. doi:10.1051/0004-6361/202038649. 2020. [3] Nedelcu D.A., Birlan M., Turcu V., Boaca I., Badescu O., Gornea A., Sonka A.B., Blagoi O., Danescu C., Paraschiv P. Meteorites Orbits Reconstruction by Optical Imaging (MOROI) Network. Romanian Astronomical Journal 28(1), 57 – 65. 2018.
Published: 2021

18. Luminous efficiency based on FRIPON meteors and limitations of ablation models

Author: Björn Poppe, B. Zanda, C. A. Volpicelli, J. Vaubaillon, Jim Rowe, Detlef Koschny, Pierre Vernazza, O. Hernandez, François Colas, Dan Alin Nedelcu, M. Forcier, Sylvain Bouley, Theresa Ott, Agustín Sánchez-Lavega, Josep M. Trigo-Rodríguez, Cristina Knapic, S. Rasetti, Esther Drolshagen, Daniele Gardiol, A. Toni, M. Di Carlo, Giovanni Pratesi, H. Lamy, Giovanni B. Valsecchi, Ludovic Ferrière, Sonia Zorba, E. Peña-Asensio, Mirel Birlan, Albert Rimola, A. Malgoyre, M. Jobin, S. Jeanne, Ashley J. King, Albino Carbognani, Emmanuel Jehin, Dario Barghini, Gerhard Drolshagen, W. Riva, G. M. Stirpe, A. Grandchamps, M. Di Martino, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Meteor (satellite), 010504 meteorology & atmospheric sciences, Meteors, Context (language use), Astrophysics, 01 natural sciences, meteorites, techniques: photometric, 0103 physical sciences, meteorites, meteors, meteoroids, minor planets, asteroids: general, comets: general, techniques: photometric, atmospheric effects, methods: data analysis, Emission spectrum, meteors, data analysis [Methods], meteoroids, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Meteoroid, comets: general, photometric [Techniques], Minor planets, general [Comets], Astronomy and Astrophysics, Meteoroids, Atmospheric effects, methods: data analysis, asteroids: general, Wavelength, Meteorite, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], minor planets, Luminous efficacy, Interplanetary spaceflight, general [Asteroids], Meteorites, atmospheric effects
Abstract: Drolshagen, E., et al., [Context] In meteor physics, the luminous efficiency τ is used to convert the meteor's magnitude to the corresponding meteoroid's mass. However, a lack of sufficiently accurate verification methods or adequate laboratory tests mean that discussions around this parameter are a subject of controversy. [Aims] In this work, we aim to use meteor data obtained by the Fireball Recovery and InterPlanetary Observation to calculate the luminous efficiencies of the recorded meteors. We also show the limitations of the methods presented herein. [Methods] Deceleration-based formulas were used to calculate the masses of the pre-atmospheric meteoroids. These can in turn be compared to the meteor brightnesses to assess the luminous efficiencies of the recorded objects. Fragmentation of the meteoroids is not considered within this model. Good measurements of the meteor deceleration are required. [Results] We find τ-values, as well as the shape change coefficients, of 294 meteors and fireballs with determined masses in the range of 10-6-100 kg. The derived τ-values have a median of τmedian = 2.17%. Most of them are of the order of 0.1-10%. We present how our values are obtained, compare them with data reported in the literature, and discuss several methods. A dependence of τ on the pre-atmospheric velocity of the meteor, ve, is noticeable with a relation of τ = 0.0023 ve2.3. Furthermore, a dependence of τ on the initial meteoroid mass, Me, is found with negative linear behaviour in log-log space: τ = 0.48 Me-0.47. [Conclusions] The higher luminous efficiency of fast meteors could be explained by the higher amount of energy released. Fast meteoroids produce additional emission lines that radiate more efficiently in specific wavelengths due to the appearance of the so-called second component of higher temperature. Furthermore, the negative dependence of τ on Me implies that the radiation of smaller meteoroids is more efficient. The results of this study also show the limitations of the ablation-based model for the determination of the luminous efficiency.
Published: 2021

19. First light of SOVAG, a spectrograph for visible and near-infrared observation of asteroids

Author: A. Nedelcu, J. Dubois, François Colas, S. Fornasier, Benoit Carry, Pascal Morfin, Mirel Birlan, David Darson, Pierre Vernazza, F. Cochard, D. Perna, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES)
Subjects: Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Near-infrared spectroscopy, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, First light, 01 natural sciences, law.invention, Telescope, Phase angle (astronomy), Space and Planetary Science, Observatory, Asteroid, law, [SDU]Sciences of the Universe [physics], 0103 physical sciences, Astrophysics::Earth and Planetary Astrophysics, Spectroscopy, 010303 astronomy & astrophysics, Spectrograph, Astrophysics::Galaxy Astrophysics, ComputingMilieux_MISCELLANEOUS
Abstract: Spectroscopy in the visible and near-infrared has been the main tool for characterising the surface properties of asteroids for decades. For a given target, the two wavelength regimes are usually acquired by different telescopes/instruments, separated by years. They are seldom obtained simultaneously. However, it is not straightforward to combine datasets from different sources because of the spectral reddening linked with phase angle. We present the first-light result of SOVAG (Spectrographe pour l’Observations dans le Visible et infrarouge proche d’Asteroides Geocroiseurs), a new concept of spectrograph for observing both wavelength ranges at the same time. It is compact in design and portable. We developed a prototype of this instrument between 2016 and 2018. In July 2018, we mounted SOVAG on the 1 m-telescope in Pic du Midi observatory (for which it was designed) and conducted its on-sky first light experiment. We present a spectrum of (4) Vesta which demonstrates the reliability of observations and the accuracy of the calibration. Ongoing development will allow us to push observation-limits toward fainter objects.
Published: 2021

20. Cavezzo, the first Italian meteorite recovered by the PRISMA fireball network. Orbit, trajectory, and strewn-field

Author: C. A. Volpicelli, Enrico Cascone, M. Belluso, Stefano Basso, Riccardo Smareglia, Cyril Blanpain, A. Andreis, G. Monti, M. E. Bertaina, S. Masiero, Tonino Pisanu, G. Interrante, F. Lippolis, G. Tigani Sava, G. Valente, D. Barghini, Sonia Zorba, Alberto Buzzoni, V. Gagliarducci, M. Soldi, Fabio Manca, Cristina Knapic, Cristian Carli, M. Montesarchio, Giovanni Pratesi, S. Rubinetti, D. Licchelli, T. Avoscan, A. Misiano, D. Cricchio, F. Federici, P. Colombetti, M. Romeo, G. Ascione, Daniele Gardiol, Alberto Cellino, A. Gerardi, François Colas, M. Suvieri, F. Strafella, R. Di Luca, F. Bernardi, A. Nastasi, J. L. Rault, S. Jeanne, C. Simoncelli, R. Stanga, Monica Lazzarin, C. Romeni, C. Cattaneo, S. Rasetti, Albino Carbognani, A. Malgoyre, Jader Monari, P. Demaria, Carla Taricco, M. Tombelli, Gabriele Giuli, Giuseppe Leto, A. Di Dato, N. Rizzi, M. Di Carlo, R. Serra, A. Pegoraro, Sylvain Bouley, S. Pietronave, Matteo Albani, R. Baldini, D. Guidetti, F. Salvati, M. Montemaggi, G. D’Agostino, Elisa Londero, A. Zollo, Chiara Marmo, F. Mannucci, W. Riva, J. Vaubaillon, Brigitte Zanda, Mirel Birlan, M. Rigoni, P. Morini, Jérôme Gattacceca, U. Repetti, M. Pavone, R. Zagarella, G. Cremonese, S. Meucci, S. Lera, R. Bellitto, M. D’Elia, A. Balestrero, F. Affaticati, M. De Maio, T. Carriero, R. Masi, S. Mancuso, Giovanni B. Valsecchi, Emilio Molinari, N. Pugno, R. Salerno, R. Bonino, R. Pardini, Pierre Vernazza, P. Russo, A. Bussi, V. Moggi Cecchi, C. Benna, G. M. Stirpe, K. Boros, J. Lecubin, P. Bacci, Gabriele Umbriaco, M. Costa, D. Selvestrel, E. Pace, M. Di Martino, R. Vairetti, E. Colombi, L. Betti, P. Trivero, P. Volpini, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Gardiol, D., Barghini, D., Buzzoni, A., Carbognani, A., Di Carlo, M., Di Martino, M., Knapic, C., Londero, E., Pratesi, G., Rasetti, S., Riva, W., Salerno, R., Stirpe, G. M., Valsecchi, G. B., Volpicelli, C. A., Zorba, S., Colas, F., Zanda, B., Bouley, S., Jeanne, S., Malgoyre, A., Birlan, M., Blanpain, C., Gattacceca, J., Lecubin, J., Marmo, C., Rault, J. L., Vaubaillon, J., Vernazza, P., Affaticati, F., Albani, M., Andreis, A., Ascione, G., Avoscan, T., Bacci, P., Baldini, R., Balestrero, A., Basso, S., Bellitto, R., Belluso, M., Benna, C., Bernardi, F., Bertaina, M. E., Betti, L., Bonino, R., Boros, K., Bussi, A., Carli, C., Carriero, T., Cascone, E., Cattaneo, C., Cellino, A., Colombetti, P., Colombi, E., Costa, M., Cremonese, G., Cricchio, D., D'Agostino, G., D'Elia, M., De Maio, M., Demaria, P., Di Dato, A., Di Luca, R., Federici, F., Gagliarducci, V., Gerardi, A., Giuli, G., Guidetti, D., Interrante, G., Lazzarin, M., Lera, S., Leto, G., Licchelli, D., Lippolis, F., Manca, F., Mancuso, S., Mannucci, F., Masi, R., Masiero, S., Meucci, S., Misiano, A., Moggi Cecchi, V., Molinari, E., Monari, J., Montemaggi, M., Montesarchio, M., Monti, G., Morini, P., Nastasi, A., Pace, E., Pardini, R., Pavone, M., Pegoraro, A., Pietronave, S., Pisanu, T., Pugno, N., Repetti, U., Rigoni, M., Rizzi, N., Romeni, C., Romeo, M., Rubinetti, S., Russo, P., Salvati, F., Selvestrel, D., Serra, R., Simoncelli, C., Smareglia, R., Soldi, M., Stanga, R., Strafella, F., Suvieri, M., Taricco, C., Tigani Sava, G., Tombelli, M., Trivero, P., Umbriaco, G., Vairetti, R., Valente, G., Volpini, P., Zagarella, R., Zollo, A., Gardiol D., Barghini D., Buzzoni A., Carbognani A., Di Carlo M., Di Martino M., Knapic C., Londero E., Pratesi G., Rasetti S., Riva W., Salerno R., Stirpe G.M., Valsecchi G.B., Volpicelli C.A., Zorba S., Colas F., Zanda B., Bouley S., Jeanne S., Malgoyre A., Birlan M., Blanpain C., Gattacceca J., Lecubin J., Marmo C., Rault J.L., Vaubaillon J., Vernazza P., Affaticati F., Albani M., Andreis A., Ascione G., Avoscan T., Bacci P., Baldini R., Balestrero A., Basso S., Bellitto R., Belluso M., Benna C., Bernardi F., Bertaina M.E., Betti L., Bonino R., Boros K., Bussi A., Carli C., Carriero T., Cascone E., Cattaneo C., Cellino A., Colombetti P., Colombi E., Costa M., Cremonese G., Cricchio D., D'Agostino G., D'Elia M., De Maio M., Demaria P., Di Dato A., Di Luca R., Federici F., Gagliarducci V., Gerardi A., Giuli G., Guidetti D., Interrante G., Lazzarin M., Lera S., Leto G., Licchelli D., Lippolis F., Manca F., Mancuso S., Mannucci F., Masi R., Masiero S., Meucci S., Misiano A., Moggi Cecchi V., Molinari E., Monari J., Montemaggi M., Montesarchio M., Monti G., Morini P., Nastasi A., Pace E., Pardini R., Pavone M., Pegoraro A., Pietronave S., Pisanu T., Pugno N., Repetti U., Rigoni M., Rizzi N., Romeni C., Romeo M., Rubinetti S., Russo P., Salvati F., Selvestrel D., Serra R., Simoncelli C., Smareglia R., Soldi M., Stanga R., Strafella F., Suvieri M., Taricco C., Tigani Sava G., Tombelli M., Trivero P., Umbriaco G., Vairetti R., Valente G., Volpini P., Zagarella R., Zollo A., and ITA
Subjects: meteoroids -methods: data analysis -techniques: image processing, 010502 geochemistry & geophysics, 01 natural sciences, Strewn field, meteorites, 0103 physical sciences, meteors, meteoroids, 010303 astronomy & astrophysics, meteoroid, 0105 earth and related environmental sciences, Physics, Meteoroid, image processing, methods: data analysis, techniques, meteor, Astronomy, Astronomy and Astrophysics, meteorite, Meteorite, Space and Planetary Science, [SDU]Sciences of the Universe [physics], data analysi [methods], Trajectory, Orbit (control theory)
Abstract: Two meteorite pieces have been recovered in Italy, near the town of Cavezzo (Modena), on 2020 January 4th. The associated fireball was observed on the evening of New Year’s Day 2020 by eight all-sky cameras of the PRISMA fireball network, a partner of FRIPON. The computed trajectory had an inclination angle of approximately 68° and a velocity at infinity of 12.8 km s−1. Together with the relatively low terminal height, estimated as 21.5 km, those values were indicating the significant possibility of a meteorite dropping event, as additionally confirmed by the non-zero residual total mass. The strewn-field was computed taking into account the presence of two bright light flashes, revealing that the meteoroid had been very likely subject to fragmentation. Three days after the event, two samples, weighing 3.1 and 52.2 g, were collected as a result of a dedicated field search and thanks to the involvement of the local people. The two pieces were immediately recognized as freshly fallen fragments of meteorite. The computed orbital elements, compared with the ones of known Near-Earth Asteroids from the NEODyS database, are compatible with one asteroid only; 2013 VC10. The estimated original mass of the meteoroid, 3.5 kg, and size, approximately 13 cm, is so far the smallest among the current 35 cases in which meteorites were recovered from precise strewn-field computation thanks to observational data. This result demonstrates the effectiveness of accurate processing of fireball network data even on challenging events generated by small size meteoroids.
Published: 2021

21. Apophis 2029: Decadal Opportunity for the Science of Planetary Defense

Author: William C. Danchi, Patrick Michel, Patrick A. Taylor, James F. Bell, Michael Marsset, Daniel J. Scheeres, Jessica M. Sunshine, Derek C. Richardson, D. Souami, William F. Bottke, Olivier S. Barnouin, J. Souchay, J. V. DeMartini, Yaeji Kim, Mirel Birlan, Terik Daly, Michael C. Nolan, Carol A. Raymond, Masatoshi Hirabayashi, Joshua T.S. Cahill, Humberto Campins, Francesca E. DeMeo, Daniel D. Durda, N. Moskovitz, Joseph A. Nuth, Donald K. Yeomans, Alex Parker, Andy Cheng, M. Brozovic, Richard P. Binzel, Ryan S. Park, Flaviane Venditti, Brent W. Barbee, P. W. Chodas, Anthony Freeman, Kim Reh, Paul Sava, Lucy F. Lim, Anne Virkki, A. C. Boley, Observatoire de Paris, Université Paris sciences et lettres (PSL), Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Namur Center for Complex Systems [Namur] (NaXys), Université de Namur [Namur] (UNamur), Systèmes de Référence Temps Espace (SYRTE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS, Laboratoire Lagrange, Nice, France
Subjects: [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Comet, Geosynchronous orbit, Potentially hazardous object, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Context (language use), Mars Exploration Program, Astrobiology, Jupiter, Planetary science, 13. Climate action, Asteroid, [SDU]Sciences of the Universe [physics], Environmental science, ComputingMilieux_MISCELLANEOUS
Abstract: International audience; Many advancements in planetary science are achieved by seizing upon the opportunity created by rare natural events (e.g. comet Shoemaker-Levy 9 Jupiter impact; 1994) and by planned physical interactions (e.g. Deep Impact into comet Tempel 1; 2005). A forthcoming opportunity to seize upon a natural physical “experiment” occurs on April 13, 2029 with the unprecedentedly close Earth encounter by the large 340m asteroid (99942) Apophis. On that date, nature is performing the “experiment” of subjecting the physical body of Apophis to Earth’s tidal torques as it approaches to within 31,000 km of Earth’s surface, a distance that is closer than orbiting geosynchronous satellites.A potentially hazardous asteroid (PHA) as large as Apophis encountering Earth this closely (within 0.1 lunar distances) is, on average, a once-per-thousand year event. (In context, Apophis is 7 times larger and 350 times more massive than the Tunguska 1908 impactor; 5000 times more massive than Chelyabinsk 2013.) Because of this event’s incredible rarity, knowledge gained through measurements and outcomes of the Apophis 2029 “natural experiment” are clearly a decadal, if not millennial, opportunity for planetary science. Most specifically, this knowledge opportunity is for the science supporting planetary defense. Further, on April 13, 2029 all of Earth will be watching: Apophis will be visible to the naked eye speeding across the evening sky for an estimated 2 billion people spanning western Europe and northern Africa.In this White Paper we outline our current best understanding, and uncertainties, for scientific advances in the physical study of potentially hazardous asteroids that may be achievable by measuring physical changes of Apophis’ spin, surface structure, and/or shape configuration inresponse to Earth’s tidal torques. If tidal torques themselves, or surface configuration changes induce any measurable seismic vibration signal inside Apophis, a new field of asteroid seismology has the potential to be born. Over six decades of planetary science, seismology has been achieved beyond Earth for only two planetary worlds: Moon and Mars.With this White Paper, we take no position on how to implement specific investigations capable of achieving the science advances offered by the Apophis 2029 opportunity. Instead we advocate that competitive selection of investigations, be they theoretical or observational (ground-based, space-based, or in situ), be executed under the direction of NASA’s Planetary Defense Coordination Office, with a projected and perhaps necessarily augmented budget capable of supporting them. International collaboration is strongly encouraged.Thus, summarizing in four specific points, we urge the framers of the Decadal Survey to:• Recognize the decadal, if not millennial, opportunity for the science of planetary defense presented by the Apophis 2029 once-per-thousand-year “natural experiment.”• Prioritize as a top-level planetary defense science goal modeling and measuring the physical outcome on Apophis exerted by Earth’s tidal torques so as to achieve the greatest possible new insights into the physical nature, including the internal structure, of PHAs.• Recognize that time is of the essence for defining and implementing investigations of physical effects on Apophis, particularly if in situ measurements are to be considered. An Apophis 2029 Science Definition Team may be prescribed.• Recognize that the achievable knowledge of PHAs presented by the Apophis 2029 opportunity could have immeasurable benefits to the future of humanity, in the highly unlikely, but not impossible necessity to mitigate a future impact threat
Published: 2021

22. Evidence for differentiation of the most primitive small bodies

Author: Pierre Vernazza, Tadeusz Michalowski, Bin Yang, Matti Viikinkoski, Brian Warner, Agnieszka Kryszczyńska, Alexis Drouard, Alexander Storrs, Franck Marchis, J. Grice, François Colas, Patrick Michel, Laurent Jorda, Romain Fétick, Przemyslaw Bartczak, Arthur Vigan, Josef Ďurech, Marc Neveu, Frédéric Vachier, Julie Castillo-Rogez, Emmanuel Jehin, Michael Marsset, Josef Hanus, Nicolas Rambaux, Josselin Desmars, Mikko Kaasalainen, Marin Ferrais, Jérôme Berthier, Olivier Witasse, Philippe Lamy, Zouhair Benkhaldoun, E. Podlewska-Gaca, Fabrice Cipriani, Grzegorz Dudziński, Thierry Fusco, Raoul Behrend, Christophe Dumas, Anna Marciniak, Mirel Birlan, M. Pajuelo, Paolo Tanga, Benoit Carry, T. Santana-Ros, Mark A. Wieczorek, Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), University of Maryland [College Park], University of Maryland System, NASA Goddard Space Flight Center (GSFC), Institute of Astronomy [Prague], Charles University [Prague], Space Sciences, Technologies and Astrophysics Research Institute (STAR), Université de Liège, Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), Department of Mathematics [Tampere], Tampere University of Technology [Tampere] (TUT), Astronomical Observatory [Poznan], Adam Mickiewicz University in Poznań (UAM), Geneva Observatory, University of Geneva [Switzerland], Oukaimeden Observatory, University of Cadi Ayyad (UCA), Astronomical Institute of Romanian Academy, Romanian Academy, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Institut Polytechnique des Sciences Avancées (IPSA), Thirty Meter Telescope Observatory, The Open University [Milton Keynes] (OU), University of Tampere [Finland], HELIOS - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), SETI Institute, Pontificia Universidad Católica del Perú (PUCP), Institute of Physics [Szczecin], University of Szczecin, Universidad de Alicante, Institut de Ciencies del Cosmos (ICCUB), Universitat de Barcelona (UB), Towson University [Towson, MD, United States], Center for Solar System Studies (CS3), European Southern Observatory (ESO), Czech Science Foundation, Charles University (Czech Republic), Generalitat de Catalunya, Ministerio de Ciencia, Innovación y Universidades (España), National Science Foundation (US), Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Charles University [Prague] (CU), Université de Genève = University of Geneva (UNIGE), Université Cadi Ayyad [Marrakech] (UCA), Agence Spatiale Européenne = European Space Agency (ESA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Pontificia Universidad Católica del Perú = Pontifical Catholic University of Peru (PUCP), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Tampere University, and Computing Sciences
Subjects: asteroids, Solar System, 010504 meteorology & atmospheric sciences, individual: Sylvia [Asteroids], individual: Sylvia [Minor planets, asteroids], FOS: Physical sciences, general [Minor planets, asteroids], Astrophysics, 01 natural sciences, Kuiper belt, Jupiter, Interplanetary dust cloud, Neptune, Física Aplicada, 0103 physical sciences, 111 Mathematics, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Nodal precession, Sylvia, Minor planets, Astronomy and Astrophysics, general [Kuiper belt], 113 Computer and information sciences, Asteroids: general, Meteorite, 115 Astronomy and space science, 13. Climate action, Space and Planetary Science, Asteroid, [SDU]Sciences of the Universe [physics], Carbonaceous chondrite, Minor plantes, Asteroids: individual: Sylvia, Kuiper belt: general, general [Asteroids], Astrophysics - Earth and Planetary Astrophysics
Abstract: Carri, B., et al., [Context] Dynamical models of Solar System evolution have suggested that the so-called P- and D-type volatile-rich asteroids formed in the outer Solar System beyond Neptune's orbit and may be genetically related to the Jupiter Trojans, comets, and small Kuiper belt objects (KBOs). Indeed, the spectral properties of P- and D-type asteroids resemble that of anhydrous cometary dust. Aims. We aim to gain insights into the above classes of bodies by characterizing the internal structure of a large P- and D-type asteroid. [Methods] We report high-angular-resolution imaging observations of the P-type asteroid (87) Sylvia with the Very Large Telescope Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument. These images were used to reconstruct the 3D shape of Sylvia. Our images together with those obtained in the past with large ground-based telescopes were used to study the dynamics of its two satellites. We also modeled Sylvia's thermal evolution. [Results] The shape of Sylvia appears flattened and elongated (a/b 1.45; a/c 1.84). We derive a volume-equivalent diameter of 271 ± 5 km and a low density of 1378 ± 45 kg m-3. The two satellites orbit Sylvia on circular, equatorial orbits. The oblateness of Sylvia should imply a detectable nodal precession which contrasts with the fully-Keplerian dynamics of its two satellites. This reveals an inhomogeneous internal structure, suggesting that Sylvia is differentiated. [Conclusions] Sylvia's low density and differentiated interior can be explained by partial melting and mass redistribution through water percolation. The outer shell should be composed of material similar to interplanetary dust particles (IDPs) and the core should be similar to aqueously altered IDPs or carbonaceous chondrite meteorites such as the Tagish Lake meteorite. Numerical simulations of the thermal evolution of Sylvia show that for a body of such a size, partial melting was unavoidable due to the decay of long-lived radionuclides. In addition, we show that bodies as small as 130-150 km in diameter should have followed a similar thermal evolution, while smaller objects, such as comets and the KBO Arrokoth, must have remained pristine, which is in agreement with in situ observations of these bodies. NASA Lucy mission target (617) Patroclus (diameter ≈140 km) may, however, be differentiated., This work has been supported by the Czech Science Foundation through grants 20-08218S (J. Hanuš, J. Ďurech) and by the Charles University Research program No. UNCE/SCI/023. The work of TSR was carried out through grant APOSTD/2019/046 by Generalitat Valenciana (Spain). This work was supported by the MINECO (Spanish Ministry of Economy) through grant RTI2018-095076-B-C21 (MINECO/FEDER, UE). This material is partially based upon work supported by the National Science Foundation under Grant No. 1743015.
Published: 2021

23. Binary asteroid (31) Euphrosyne: ice-rich and nearly spherical

Author: Emmanuel Jehin, Josef Hanus, Christophe Dumas, Franck Marchis, Frédéric Vachier, Nicolas Rambaux, Pierre Vernazza, Romain Fétick, Marin Ferrais, Zouhair Benkhaldoun, M. Pajuelo, Paolo Tanga, Bin Yang, A. Marciniak, Olivier Witasse, Matti Viikinkoski, E. Podlewska-Gaca, Fabrice Cipriani, Ondrej Chrenko, Philippe Lamy, Laurent Jorda, François Colas, J. Grice, Tadeusz Michalowski, Julie Castillo-Rogez, Josef Ďurech, Mikko Kaasalainen, Grzegorz Dudziński, Michael Marsset, Patrick Michel, Mirel Birlan, Przemyslaw Bartczak, Alexis Drouard, Toni Santana-Ros, Jérôme Berthier, Miroslav Brož, Arthur Vigan, P. Ševeček, Benoit Carry, Thierry Fusco, Agnieszka Kryszczyńska, European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Institute of Astronomy [Prague], Charles University [Prague] (CU), Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), University of Tampere [Finland], Space Sciences, Technologies and Astrophysics Research Institute (STAR), Université de Liège, Astronomical Observatory [Poznan], Adam Mickiewicz University in Poznań (UAM), Search for Extraterrestrial Intelligence Institute (SETI), Astronomical Institute of Romanian Academy, Romanian Academy, Oukaimeden Observatory, Université Cadi Ayyad [Marrakech] (UCA), Thirty Meter Telescope Observatory, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), DOTA, ONERA, Université Paris Saclay [Palaiseau], ONERA-Université Paris-Saclay, School of Physical Sciences [Milton Keynes], Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Pontificia Universidad Católica del Perú (PUCP), Universidad de Alicante, Institut de Ciencies del Cosmos (ICCUB), Universitat de Barcelona (UB), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Pontificia Universidad Católica del Perú = Pontifical Catholic University of Peru (PUCP), Czech Science Foundation, Charles University (Czech Republic), Ministry of Education, Youth and Sports (Czech Republic), Centre National de la Recherche Scientifique (France), National Aeronautics and Space Administration (US), Generalitat Valenciana, Ministerio de Economía y Competitividad (España), Fonds de la Recherche Scientifique (Fédération Wallonie-Bruxelles), and Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal
Subjects: individual: (31) Euphrosyne / minor planets [Asteroids], 010504 meteorology & atmospheric sciences, general [Minor planets, asteroids], FOS: Physical sciences, Astrophysics, Asteroids: individual: (31) Euphrosyne / minor planets, 01 natural sciences, Sphericity, law.invention, Techniques: high angular resolution, Impact crater, law, Física Aplicada, 0103 physical sciences, observational [Methods], Circular orbit, 010303 astronomy & astrophysics, individual: (31) Euphrosyne [Minor planets, asteroids], ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Physics, [PHYS]Physics [physics], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astronomy and Astrophysics, high angular resolution [Techniques], Orbit, Asteroids: general, Methods: observational / minor planets, Space and Planetary Science, Asteroid, Satellite, observational / minor planets [Methods], Hydrostatic equilibrium, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], general [Asteroids], Astrophysics - Earth and Planetary Astrophysics, Shape analysis (digital geometry)
Abstract: Aims. Asteroid (31) Euphrosyne is one of the biggest objects in the asteroid main belt and it is also the largest member of its namesake family. The Euphrosyne family occupies a highly inclined region in the outer main belt and contains a remarkably large number of members, which is interpreted as an outcome of a disruptive cratering event. Methods. The goals of this adaptive-optics imaging study are threefold: to characterize the shape of Euphrosyne, to constrain its density, and to search for the large craters that may be associated with the family formation event. Results. We obtained disk-resolved images of Euphrosyne using SPHERE/ZIMPOL at the ESO 8.2 m VLT as part of our large program (ID: 199.C-0074, PI: Vernazza). We reconstructed its 3D shape via the ADAM shape modeling algorithm based on the SPHERE images and the available light curves of this asteroid. We analyzed the dynamics of the satellite with the Genoid meta-heuristic algorithm. Finally, we studied the shape of Euphrosyne using hydrostatic equilibrium models. Conclusions. Our SPHERE observations show that Euphrosyne has a nearly spherical shape with the sphericity index of 0.9888 and its surface lacks large impact craters. Euphrosyne's diameter is 268 ± 6 km, making it one of the top ten largest main belt asteroids. We detected a satellite of Euphrosyne - S/2019 (31) 1 - that is about 4 km across, on a circular orbit. The mass determined from the orbit of the satellite together with the volume computed from the shape model imply a density of 1665 ± 242 kg m-3, suggesting that Euphrosyne probably contains a large fraction of water ice in its interior. We find that the spherical shape of Euphrosyne is a result of the reaccumulation process following the impact, as in the case of (10) Hygiea. However, our shape analysis reveals that, contrary to Hygiea, the axis ratios of Euphrosyne significantly differ from those suggested by fluid hydrostatic equilibrium following reaccumulation., This work has been supported by the Czech Science Foundation through grant 18-09470S (J. Hanuš, O. Chrenko, P. Ševecˇek) and by the Charles University Research program No. UNCE/SCI/023. M.B. was supported by the Czech Science Foundation grant 18-04514J. Computational resources were supplied by the Ministry of Education, Youth and Sports of the Czech Republic under the projects CESNET (LM2015042) and IT4Innovations National Supercomputing Centre (LM2015070). P. Vernazza, A. Drouard, M. Ferrais and B. Carry were supported by CNRS/INSU/PNP. M.M. was supported by the National Aeronautics and Space Administration under grant No. 80NSSC18K0849 issued through the Planetary Astronomy Program. The work of TSR was carried out through grant APOSTD/2019/046 by Generalitat Valen-ciana (Spain). This work was supported by the MINECO (Spanish Ministry of Economy) through grant RTI2018-095076-B-C21 (MINECO/FEDER, UE). The research leading to these results has received funding from the ARC grant for Concerted Research Actions, financed by the Wallonia-Brussels Federation. TRAPPIST is a project funded by the Belgian Fonds (National) de la Recherche Scientifique (F.R.S.-FNRS) under grant FRFC 2.5.594.09.F. TRAPPIST-North is a project funded by the Université de Liège, and performed in collaboration with Cadi Ayyad University of Marrakesh. E. Jehin is a FNRS Senior Research Associate.
Published: 2020

24. A case study of the May 30, 2017, Italian fireball

Author: Mirel Birlan, D. Barghini, Alberto Buzzoni, P. Demaria, L. Maquet, J. Vaubaillon, Brigitte Zanda, Daniele Gardiol, Giovanni B. Valsecchi, Chiara Marmo, M. Di Martino, Jerome Gattacceca, Sonia Zorba, M. Di Carlo, Pierre Vernazza, Cristina Knapic, Jean-Louis Rault, Elisa Londero, P. Trivero, François Colas, F. Zanotti, Sylvain Bouley, S. Rasetti, C. A. Volpicelli, Albino Carbognani, D. Valeri, M. Morini, D. Selvestrel, Astronomical Observatory of the Autonomous Region of the Aosta Valley (OAVDA), INAF - Osservatorio Astrofisico di Torino (OATo), Istituto Nazionale di Astrofisica (INAF), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Géosciences Paris Saclay (GEOPS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València (UPV), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Interactions et dynamique des environnements de surface (IDES), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Universitat Politecnica de Valencia (UPV), UMS Nano-analyses (UNA), Centre National de la Recherche Scientifique (CNRS), Géosciences Paris Sud (GEOPS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), and Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA)
Subjects: Physics, Earth and Planetary Astrophysics (astro-ph.EP), [PHYS]Physics [physics], Meteoroid, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], media_common.quotation_subject, General Physics and Astronomy, FOS: Physical sciences, Astrophysics, 010502 geochemistry & geophysics, 01 natural sciences, 13. Climate action, Sky, 0103 physical sciences, Atmospheric dynamics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, media_common, Astrophysics - Earth and Planetary Astrophysics
Abstract: On May 30th, 2017 at about 21h 09m 17s UTC a green bright fireball crossed the sky of north-eastern Italy. The fireball path was observed from some all-sky cameras starting from a mean altitude of $81.1 \pm 0.2$ km (Lat. $44.369^{\circ} \pm 0.002^{\circ}$ N; Long. $11.859^{\circ} \pm 0.002^{\circ}$ E) and extinct at $23.3 \pm 0.2$ km (Lat. $45.246^{\circ} \pm 0.002^{\circ}$ N; Long. $12.046^{\circ} \pm 0.002^{\circ}$ E), between the Italian cities of Venice and Padua. In this paper, on the basis of simple physical models, we will compute the atmospheric trajectory, analize the meteoroid atmospheric dynamics, the dark flight phase (with the strewn field) and compute the best heliocentric orbit of the progenitor body. Search for meteorites on the ground has not produced any results so far., 19 pages, 17 figures. Accepted for publication in The European Physical Journal PLUS
Published: 2020

25. The EU H2020 programme NEOROCKS

Author: Fabrizio Bernardi, Claudiu Teodorescu, Colin Snodgrass, A. Cellino, Marek Banaszkiewicz, Monica Lazzarin, Julia de Leon, M. A. Barucci, Elisabetta Dotto, Sara Banchi, Benoit Carry, Jaime Nomen Torres, Noelia Sánchez Ortiz, Ettore Perozzi, Petr Pravec, Davide Perna, Mirel Birlan, and Elena Mazzotta Epifani
Subjects: Near Earth Asteroids, NEOROCKS, Horizon2020, Horizon2020, Near Earth Asteroids, NEOROCKS
Abstract: The research about Near Earth Objects (NEOs) is a major topic in planetary science. One reason is the potential hazard some of them pose to human beings and, more in general, to life on our planet. Moreover, the physical characterization of NEOs allows us to put constraints on the material accreted in the protoplanetary nebula at different solar distances and can give us insights into the early processes that governed the formation and the evolution of planets - including the delivery of water and organics to Earth -, and into further evolutionary processes that acted on asteroid since their formation - such as collisions and non-gravitational effects. The “NEOROCKS - The NEO Rapid Observation, Characterization and Key Simulations” Collaborative Research Project has been recently approved to address the topic c) “Improvement of our knowledge of the physical characteristics of the NEO population” of the call SU-SPACE-23-SEC-2019 from the Horizon 2020 - Work Programme 2018-2020 Leadership in Enabling and Industrial Technologies – Space. The aims of NEOROCKS are: to develop and validate advanced mathematical methods and innovative algorithms for NEO orbit determination and impact monitoring; to organize follow-up astronomical observations of NEOs efficiently, in order to obtain high-quality data needed to derive their physical properties, giving priority to timely addressing potentially hazardous objects; to improve dramatically statistical analysis, modelling and computer simulations aimed to understand the physical nature of NEOs, focussing on small size objects, which are of uttermost importance for designing effective impact mitigation measures in space and on the ground; to ensure maximum visibility and dissemination of the data beyond the timeline of the project, by hosting it in an existing astronomical data center facility; to foster European and international cooperation on NEO physical characterization, providing scenarios and roadmaps with the potential to scale-up at a global level the experience gained during the project; to apply and guarantee continuity of educational and public outreach activities needed to improve significantly public understanding and perception of the asteroid hazard, counteracting the spreading of “fake news” and unjustified alarms. Acknowledgement: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 870403 (project NEOROCKS).
Published: 2020

26. The violent collisional history of aqueously evolved (2) Pallas

Author: Alexis Drouard, Franck Marchis, Romain Fétick, Arthur Vigan, Miroslav Brož, Julie Castillo-Rogez, Herve Le Coroller, Christophe Dumas, Josef Hanus, Toni Santana-Ros, Paolo Tanga, Patrick Michel, Matti Viikinkoski, Mirel Birlan, E. Podlewska-Gaca, Fabrice Cipriani, Bin Yang, Nicolas Rambaux, Mikko Kaasalainen, Thierry Fusco, Grzegorz Dudziński, Tadeusz Michalowski, Benoit Carry, Agnieszka Kryszczyńska, Przemyslaw Bartczak, P. Ševeček, Jérôme Berthier, Laurent Jorda, Josef Ďurech, Michael Marsset, François Colas, Derek C. Richardson, Marin Ferrais, A. Marciniak, Frédéric Vachier, Erik Asphaug, Pierre Vernazza, Emmanuel Jehin, Olivier Witasse, Philippe Lamy, European Commission, National Aeronautics and Space Administration (US), Generalitat Valenciana, Astrophysics Research Centre [Belfast] (ARC), Queen's University [Belfast] (QUB), Astronomical Institute of Charles University, Charles University [Prague] (CU), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Mathematics [Tampere], Tampere University of Technology [Tampere] (TUT), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Search for Extraterrestrial Intelligence Institute (SETI), Astronomical Observatory [Poznan], Adam Mickiewicz University in Poznań (UAM), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Faculty of Mathematics and Physics [Praha/Prague], Université de Liège, Les Afriques dans le monde (LAM), Sciences Po Bordeaux - Institut d'études politiques de Bordeaux (IEP Bordeaux)-Institut de Recherche pour le Développement (IRD)-Institut d'Études Politiques [IEP] - Bordeaux-Université Bordeaux Montaigne-Centre National de la Recherche Scientifique (CNRS), DOTA, ONERA, Université Paris Saclay [Châtillon], ONERA-Université Paris-Saclay, Space Sciences, Technologies and Astrophysics Research Institute (STAR), Observatoire de Haute-Provence (OHP), Institut Pythéas (OSU PYTHEAS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Amgen (Europe) GmbH, De la Préhistoire à l'Actuel : Culture, Environnement et Anthropologie (PACEA), Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Agence Spatiale Européenne = European Space Agency (ESA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Sciences Po Bordeaux - Institut d'études politiques de Bordeaux (IEP Bordeaux)-Institut de Recherche pour le Développement (IRD)-Institut d'Études Politiques [IEP] - Bordeaux-Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS), and Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal
Subjects: Very Large Telescope, 010504 meteorology & atmospheric sciences, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Asteroid (2) Pallas, Violent collisional history, Astronomy and Astrophysics, Orbital eccentricity, Astrophysics, Aqueous alteration, Albedo, 01 natural sciences, Orbital inclination, Bright spot, Impact crater, 13. Climate action, Chondrite, Asteroid, Física Aplicada, 0103 physical sciences, 010303 astronomy & astrophysics, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: et al., Asteroid (2) Pallas is the largest main-belt object not yet visited by a spacecraft, making its surface geology largely unknown and limiting our understanding of its origin and collisional evolution. Previous ground-based observational campaigns returned different estimates of its bulk density that are inconsistent with one another, one measurement1 being compatible within error bars with the icy Ceres (2.16 ± 0.01 g cm−3)2 and the other3 compatible within error bars with the rocky Vesta (3.46 ± 0.03 g cm−3)4. Here we report high-angular-resolution observations of Pallas performed with the extreme adaptive optics-fed SPHERE imager5 on the Very Large Telescope. Pallas records a violent collisional history, with numerous craters larger than 30 km in diameter populating its surface and two large impact basins that could be related to a family-forming impact. Monte Carlo simulations of the collisional evolution of the main belt correlate this cratering record to the high average impact velocity of ~11.5 km s−1 on Pallas—compared with an average of ~5.8 km s−1 for the asteroid belt—induced by Pallas’s high orbital inclination (i = 34.8°) and orbital eccentricity (e = 0.23). Compositionally, Pallas’s derived bulk density of 2.89 ± 0.08 g cm−3 (1σ uncertainty) is fully compatible with a CM chondrite-like body, as suggested by its spectral reflectance in the 3 μm wavelength region6. A bright spot observed on its surface may indicate an enrichment in salts during an early phase of aqueous alteration, compatible with Pallas’s relatively high albedo of 12–17% (refs. 7,8), although alternative origins are conceivable., Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programme 199.C-0074 (principal investigator: P.V.). This research has made use of the Keck Observatory Archive (KOA), which is operated by the W. M. Keck Observatory and the NASA Exoplanet Science Institute (NExScI), under contract with NASA. M.M. was supported by the National Aeronautics and Space Administration under grant number 80NSSC18K0849 issued through the Planetary Astronomy Program. This work was supported by the French Direction Générale de l’Armement (DGA) and Aix-Marseille Université (AMU). P.V., A.D. and B.C. were supported by CNRS/INSU/PNP. J.H., J.D. and P.S. were supported by the grant 18-09470S of the Czech Science Foundation and by the Charles University Research Programme number UNCE/SCI/023. M.Brož was supported by the grant 18-04514J of the Czech Science Foundation. E.J. is a F.R.S.-FNRS Senior Research Associate. The work of T.S.-R. was carried out through grant APOSTD/2019/046 by Generalitat Valenciana (Spain). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement number 730890.
Published: 2020

27. A basin-free spherical shape as an outcome of a giant impact on asteroid Hygiea

Author: J. Grice, Mikko Kaasalainen, F. Colas, A. Chapman, Tadeusz Michalowski, Arthur Vigan, Josef Hanus, Julie Castillo-Rogez, Róbert Szakáts, Marin Ferrais, Przemyslaw Bartczak, Benoit Carry, Miroslav Brož, Laurent Jorda, Nicolas Rambaux, Matti Viikinkoski, Grzegorz Dudziński, P. Michel, Agnieszka Kryszczyńska, Rene Duffard, Michaël Gillon, Michael Marsset, Jérôme Berthier, J. Durech, Bin Yang, Mirel Birlan, Christophe Dumas, R. Hirsch, Francesca E. DeMeo, F. Vachier, P. Lamy, Toni Santana-Ros, Thierry Fusco, Zouhair Benkhaldoun, E. Podlewska-Gaca, Fabrice Cipriani, P. Ševeček, H. Le Coroller, Olivier Witasse, A. Marciniak, F. Marchis, Emmanuel Jehin, J. L. Maestre, Alexis Drouard, Romain Fétick, Pierre Vernazza, Paolo Tanga, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Astronomical Institute of Charles University, Charles University [Prague] (CU), Tampere University of Technology [Tampere] (TUT), European Space Astronomy Centre (ESAC), European Space Agency (ESA), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Space Sciences, Technologies and Astrophysics Research Institute (STAR), Université de Liège, Astrophysics Research Centre [Belfast] (ARC), Queen's University [Belfast] (QUB), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Adam Mickiewicz University in Poznań (UAM), Institut d'Astrophysique et de Géophysique [Liège], Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), European Space Research and Technology Centre (ESTEC), Centre de Biochimie Structurale [Montpellier] (CBS), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de la Santé et de la Recherche Médicale (INSERM), DOTA, ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Université Paris Saclay (COmUE), Astronomical Observatory [Poznan], Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC), LPHEA - Departement de Physique (LPHEA), Département de physique, Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Agence Spatiale Européenne = European Space Agency (ESA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (France), Czech Science Foundation, Charles University (Czech Republic), European Commission, Université Cadi Ayyad, and Fonds de la Recherche Scientifique (Fédération Wallonie-Bruxelles)
Subjects: Rotation period, Solar System, 010504 meteorology & atmospheric sciences, Dwarf planet, VLT/SPHERE instrument, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 01 natural sciences, Sphericity, Impact crater, Física Aplicada, 0103 physical sciences, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Asteroide, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Basin-free, Astronomy, Astronomy and Astrophysics, Radius, Asteroid family, High-angular-resolution imaging observation, Asteroids, Asteroid, [SDU]Sciences of the Universe [physics], Hygiea, Astrophysics::Earth and Planetary Astrophysics, Spherical shape, Giant impact
Abstract: (10) Hygiea is the fourth largest main belt asteroid and the only known asteroid whose surface composition appears similar to that of the dwarf planet (1) Ceres1,2, suggesting a similar origin for these two objects. Hygiea suffered a giant impact more than 2 Gyr ago3 that is at the origin of one of the largest asteroid families. However, Hygeia has never been observed with sufficiently high resolution to resolve the details of its surface or to constrain its size and shape. Here, we report high-angular-resolution imaging observations of Hygiea with the VLT/SPHERE instrument (~20 mas at 600 nm) that reveal a basin-free nearly spherical shape with a volume-equivalent radius of 217 ± 7 km, implying a density of 1,944 ± 250 kg m− 3 to 1σ. In addition, we have determined a new rotation period for Hygiea of ~13.8 h, which is half the currently accepted value. Numerical simulations of the family-forming event show that Hygiea’s spherical shape and family can be explained by a collision with a large projectile (diameter ~75–150 km). By comparing Hygiea’s sphericity with that of other Solar System objects, it appears that Hygiea is nearly as spherical as Ceres, opening up the possibility for this object to be reclassified as a dwarf planet. © 2019, The Author(s), under exclusive licence to Springer Nature Limited., P.V., A.D. and B.C. were supported by CNRS/INSU/PNP. M.Broz was supported by grant 18-04514J of the Czech Science Foundation. J.H. and J.D. were supported by grant 18-09470S of the Czech Science Foundation and by the Charles University Research Programme no. UNCE/SCI/023. This project has received funding from the European Union's Horizon 2020 research and innovation programmes under grant agreement nos 730890 and 687378. This material reflects only the authors' views, and the European Commission is not liable for any use that may be made of the information contained herein. TRAPPIST-North is a project funded by the University of Liege, in collaboration with Cadi Ayyad University of Marrakech (Morocco). TRAPPIST-South is a project funded by the Belgian Fonds (National) de la Recherche Scientifique (F.R.S.-FNRS) under grant FRFC 2.5.594.09.F. E.J. and M.G. are F.R.S.-FNRS Senior Research Associates.
Published: 2019

28. Luminous efficiency of meteors derived from ablation model after assessment of its range of validity

Author: M. Di Carlo, Ashley J. King, Esther Drolshagen, Mirel Birlan, Pierre Vernazza, M. Forcier, Ludovic Ferrière, E. Peña-Asensio, Theresa Ott, Dan Alin Nedelcu, C. A. Volpicelli, François Colas, O. Hernandez, Sylvain Bouley, Daniele Gardiol, Cristina Knapic, Giovanni Pratesi, Agustín Sánchez-Lavega, Josep M. Trigo-Rodríguez, H. Lamy, G. M. Stirpe, S. Rasetti, Giovanni B. Valsecchi, Jim Rowe, Sonia Zorba, Albert Rimola, J. Vaubaillon, Brigitte Zanda, S. Jeanne, A. Toni, M. Di Martino, M. Jobin, Albino Carbognani, Björn Poppe, Gerhard Drolshagen, A. Grandchamps, Emmanuel Jehin, W. Riva, Detlef Koschny, Dario Barghini, A. Malgoyre, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Meteors, 010504 meteorology & atmospheric sciences, Context (language use), Astrophysics, 01 natural sciences, meteorites, techniques: photometric, 0103 physical sciences, Range (statistics), meteorites, meteors, meteoroids, minor planets, asteroids: general, comets: general, techniques: photometric, atmospheric effects, methods: data analysis, meteors, data analysis [Methods], meteoroids, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Meteoroid, comets: general, photometric [Techniques], Relative velocity, Minor planets, general [Comets], Astronomy and Astrophysics, Meteoroids, Function (mathematics), Atmospheric effects, methods: data analysis, asteroids: general, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, Asteroid, minor planets, Meteorities, Luminous efficacy, Interplanetary spaceflight, general [Asteroids], atmospheric effects
Abstract: Drolshagen, E., et al., [Context] The luminous efficiency, τ, can be used to compute the pre-Atmospheric masses of meteoroids from corresponding recorded meteor brightnesses. The derivation of the luminous efficiency is non-Trivial and is subject to biases and model assumptions. This has led to greatly varying results in the last decades of studies. [Aims] The present paper aims to investigate how a reduction in various observational biases can be achieved to derive (more) reliable values for the luminous efficiency. [Methods] A total of 281 meteors observed by the Fireball Recovery and InterPlanetary Observation Network (FRIPON) are studied. The luminous efficiencies of the events are computed using an ablation-based model. The relations of τ as a function of the pre-Atmospheric meteoroid velocity, ve, and mass, Me, are studied. Various aspects that could render the method less valid, cause inaccuracies, or bias the results are investigated. On this basis, the best suitable meteors were selected for luminous efficiency computations. [Results] The presented analysis shows the limits of the used method. The most influential characteristics that are necessary for reliable results for the τ computation were identified. We study the dependence of τ on the assumed meteoroid's density, ρ, and include improved ρ-values for objects with identified meteoroid stream association. Based on the discovered individual biases and constraints we create a pre-debiased subset of 54 well-recorded events with a relative velocity change >80%, a final height
Published: 2021

29. Main Belt evolution in the context of adaptive-optics observations of large asteroids

Author: Miroslav Broz, Pavel Sevecek, Pierre Vernazza, Laurent Jorda, Josef Hanus, Michael Marsset, Alexis Drouard, Matti Viikinkoski, Benoit Carry, Franck Marchis, Romain Fétick, Thierry Fusco, Mirel Birlan, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Astrophysics Research Centre [Belfast] (ARC), Queen's University [Belfast] (QUB), Department of Mathematics [Tampere], Tampere University of Technology [Tampere] (TUT), European Space Astronomy Centre (ESAC), European Space Agency (ESA), Search for Extraterrestrial Intelligence Institute (SETI), Les Afriques dans le monde (LAM), Institut de Recherche pour le Développement (IRD)-Université Bordeaux Montaigne-Institut d'Études Politiques [IEP] - Bordeaux-Sciences Po Bordeaux - Institut d'études politiques de Bordeaux (IEP Bordeaux)-Centre National de la Recherche Scientifique (CNRS), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA), Sciences Po Bordeaux - Institut d'études politiques de Bordeaux (IEP Bordeaux)-Institut de Recherche pour le Développement (IRD)-Institut d'Études Politiques [IEP] - Bordeaux-Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)
Subjects: Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: International audience; According to the size-frequency distribution (SFD) of the Main Belt, there are approximately 4 times 105 small (D = 2-3 km) projectiles which determine the surface topography of large (D > 100 km) targets. Nowadays, the topography is accessible to adaptive-optics observations by the VLT/SPHERE/ZIMPOL instrument, which typically have a pixel scale 3 km and capability to resolve Dc = 30-40 km craters in suitably illuminated areas. We used statistical collisional models (Monte-Carlo) to compute intrinsic collisional probabilities, impact velocities, expected number of catastrophic collisions, numbers of cratering events, taking into account not only mean numbers but also their dispersion. Even within the Main Belt, collisional environment can be very different from target to target.
Published: 2019

30. Calibration of fish-eye lens and error estimation on fireball trajectories: application to the FRIPON network

Author: J. Rault, Laurent Jorda, Jeremie Vaubaillon, Daniele Gardiol, François Colas, S. Jeanne, Sylvain Bouley, H. Lamy, Julien Lecubin, Albino Carbognani, Cyrille Blanpain, A. Malgoyre, Mirel Birlan, David Baratoux, Pierre Vernazza, P. Hewins, J. Gattacceca, B. Zanda, Chiara Marmo, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Géosciences Paris Sud (GEOPS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Torino (OATo), Istituto Nazionale di Astrofisica (INAF), Royal Belgian Inst Space Aeron, Ave Circulaire 3, B-1180 Brussels, Belgium, Géosciences Environnement Toulouse (GET), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Institut Pythéas (OSU PYTHEAS), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD), ITA, FRA, Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), IMCCE-CNRS, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, TO, Italy, and Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Polynomial, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Context (language use), Astrophysics, 010502 geochemistry & geophysics, 01 natural sciences, meteorites, 0103 physical sciences, Calibration, meteors, meteoroids, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Pixel, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Distortion (optics), Astronomy and Astrophysics, Astrometry, meteorites, meteors, meteoroids, [SDU]Sciences of the Universe [physics], Space and Planetary Science, Trajectory, Orbit (dynamics), astrometry, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Algorithm
Abstract: Context. Fireball networks are developing over the whole planet, with the aim of recovering meteorites and at the same time determining their orbits. The ultimate goal of such networks is to identify the parent bodies of meteorite families to achieve this, orbit accuracy is critical. Yet, the determination of an orbit relies on a long and complex reduction process including: (1) astrometry, with heavy distortion for fish-eye lenses, (2) estimation of the external bias on the observation, (3) fit of the trajectory, (4) deceleration model, and (5) actual orbit computation. Aims. Our goal is to compute accurate trajectories with an estimate of internal and external errors as realistic as possible, taking advantage of the dense observation network FRIPON (Fireball Recovery and InterPlanetary Observation Network), which comprises more than 100 cameras in France and Europe. In particular, we pay special attention to the distortion of images due to fish-eye lenses. In the present paper, we describe the analytical protocol that allows us to compute trajectories and their uncertainties. Methods. We developed a general distortion model to be used on the FRIPON fish-eye cameras. Such a model needs to be accurate even at low elevation, as most fireball observations are performed low on the horizon. The radial distortion is modelled by a nine-degree odd polynomial, hence by five parameters. In addition, we used three parameters to describe the geometry of the camera and two for non-symmetrical distortion. Lastly, we used a new statistical method taking systematic errors into account, which allows us to compute realistic confidence intervals. We tested our method on a fireball that fell on 2017-08-94 UT 00:06. Results. The accuracy of our astrometrical model for each camera is 2 arcmin (1σ), but the internal error on the fireball of 2017-08-94 UT 00:06 measurement is 0.7 arcmin (better than 1/10 pixel). We developed a method to estimate the external error considering that each station is independent and found it equal to 0.8 arcmin. Real residuals are coherent with our estimation of internal and external error for each camera, which confirms the internal consistency of our method. We discuss the advantages and disadvantages of this protocol.
Published: 2019

31. The shape of (7) Iris as evidence of an ancient large impact?

Author: Miroslav Brož, Philippe Lamy, Anna Marciniak, Josef Ďurech, J. Grice, M. Pajuelo, Paolo Tanga, Patrick Michel, Benoit Carry, Marin Ferrais, Emmanuel Jehin, Bin Yang, Alexis Drouard, Toni Santana-Ros, Frédéric Vachier, Franck Marchis, Michael Marsset, Matti Viikinkoski, Josef Hanus, Romain Fétick, Olivier Witasse, Christophe Dumas, J. Berthier, François Colas, Julie Castillo-Rogez, Agnieszka Kryszczyńska, Tadeusz Michalowski, Mikko Kaasalainen, Grzegorz Dudziński, Pierre Vernazza, Przemyslaw Bartczak, E. Podlewska-Gaca, Mirel Birlan, Thierry Fusco, H. Le Coroller, Arthur Vigan, Laurent Jorda, Fabrice Cipriani, Astronomical Institute of Charles University, Charles University [Prague] (CU), Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), Astrophysics Research Centre [Belfast] (ARC), Queen's University [Belfast] (QUB), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Department of Mathematics [Tampere], Tampere University of Technology [Tampere] (TUT), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), DOTA, ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Université Paris Saclay (COmUE), Search for Extraterrestrial Intelligence Institute (SETI), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Astronomical Observatory [Poznan], Adam Mickiewicz University in Poznań (UAM), West Pomeranian University of Technology in Szczecin (ZUT), Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, The Open University [Milton Keynes] (OU), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), TMT International Observatory, Pontificia Universidad Católica del Perú = Pontifical Catholic University of Peru (PUCP), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Technical University of Szczecin (TUNIV), Technical university of Szczecin, European Space Agency (ESA), TMT Observatory, and Pontificia Universidad Católica del Perú (PUCP)
Subjects: Solar System, Planetesimal, 010504 meteorology & atmospheric sciences, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Context (language use), Astrophysics, 01 natural sciences, methods: numerical, Impact crater, Angular diameter, 0103 physical sciences, medicine, Iris (anatomy), 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Collisional family, Astronomy and Astrophysics, 15. Life on land, medicine.anatomical_structure, 13. Climate action, Space and Planetary Science, Asteroid, [SDU]Sciences of the Universe [physics], minor planets, asteroids: individual: 7 Iris, methods: observational, Astrophysics - Earth and Planetary Astrophysics
Abstract: Asteroid (7) Iris is an ideal target for disk-resolved imaging owing to its brightness (V$\sim$7-8) and large angular size of 0.33 arcsec during its apparitions. Iris is believed to belong to the category of large unfragmented asteroids that avoided internal differentiation, implying that its current shape and topography may record the first few 100 Myr of the solar system's collisional evolution. We recovered information about the shape and surface topography of Iris from disk-resolved VLT/SPHERE/ZIMPOL images acquired in the frame of our ESO large program. We used the All-Data Asteroid Modeling (ADAM) shape reconstruction algorithm to model the 3D shape of Iris, using optical disk-integrated data and disk-resolved images from SPHERE as inputs. We analyzed the SPHERE images to infer the asteroid's global shape and the morphology of its main craters. We present the volume-equivalent diameter D$_{{\rm eq}}$=214$\pm$5 km, and bulk density $\rho$=2.7$\pm$0.3 g cm$^{-3}$ of Iris. Its shape appears to be consistent with that of an oblate spheroid with a large equatorial excavation. We identified eight putative surface features 20--40 km in diameter detected at several epochs, which we interpret as impact craters. Craters on Iris have depth-to-diameter ratios that are similar to those of analogous 10 km craters on Vesta. The bulk density of Iris is consistent with that of its meteoritic analog, namely LL ordinary chondrites. Considering the absence of a collisional family related to Iris and the number of large craters on its surface, we suggest that its equatorial depression may be the remnant of an ancient (at least 3 Gyr) impact. Iris's shape further opens the possibility that large planetesimals formed as almost perfect oblate spheroids. Finally, we attribute the difference in crater morphology between Iris and Vesta to their different surface gravities., Comment: Accepted for publication in Astronomy and Astrophysics
Published: 2019

32. Homogeneous internal structure of CM-like asteroid (41) Daphne

Author: Arthur Vigan, Agnieszka Kryszczyńska, Josef Hanus, Clark R. Chapman, Al Conrad, Eric Lagadec, Emmanuel Jehin, B. L. Enke, Michaël Gillon, Matti Viikinkoski, Pierre Vernazza, A. Marciniak, Bin Yang, Marin Ferrais, L. Bernasconi, Miriam Keppler, William J. Merline, Alexis Drouard, Alice Zurlo, Olivier Witasse, J. Grice, Peter Tamblyn, Michael Marsset, Benoit Carry, Romain Fétick, Jérôme Berthier, S. Fauvaud, Christophe Dumas, Frédéric Vachier, F. Marchis, P. Bartczak, François Colas, Agnes Fienga, Tadeusz Michalowski, Julie Castillo-Rogez, Toni Santana-Ros, Brian D. Warner, P. Lamy, Laurent Jorda, Josef Ďurech, P. Michel, Mirel Birlan, Thierry Fusco, Zouhair Benkhaldoun, E. Podlewska-Gaca, Fabrice Cipriani, Jack D. Drummond, Mikko Kaasalainen, Raoul Behrend, M. Pajuelo, Paolo Tanga, Tampere University, Computing Sciences, Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Astrophysics Research Centre [Belfast] (ARC), Queen's University [Belfast] (QUB), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Department of Space Studies [Boulder], Southwest Research Institute [Boulder] (SwRI), Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), University of Arizona, Adam Mickiewicz University in Poznań (UAM), West Pomeranian University of Technology in Szczecin (ZUT), Astronomical Observatory [Poznan], Tampere University of Technology [Tampere] (TUT), Charles University [Prague] (CU), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Starfire Optical Range [AFRL] (SOR), United States Air Force (USAF), Binary Astronomy, Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève = University of Geneva (UNIGE), Courbes de rotation d'astéroïdes, de comètes et d'étoiles variables (CdR & CdL group), CdR & CdL group, Université Cadi Ayyad [Marrakech] (UCA), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Astronomical Institute of Charles University, Observatoire du Bois de Bardon, Space Sciences, Technologies and Astrophysics Research Institute (STAR), Université de Liège, DOTA, ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Université Paris Saclay (COmUE), Environnement Méditerranéen et Modélisation des Agro-Hydrosystèmes (EMMAH), Avignon Université (AU)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut d'Astrophysique et de Géophysique [Liège], Department of Mathematics [Tampere], Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Fundació Privada Observatori Esteve Duran, Amgen (Europe) GmbH, Center for Solar System Studies (CS3), Research and Scientific Support Department of ESA, European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Universidad Diego Portales [Santiago] (UDP), ESO programs 281.C-5011 099.D-0098 199.C-0074(AFonds de la Recherche Scientifique - FNRS FRFC 2.5.594.09National Aeronautics & Space Administration (NASA) NCC 5-538National Aeronautics & Space Administration (NASA) 09-NEOO009-0001National Science Foundation (NSF) 0506716 0907766, European Project: 69W4518(1969), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Technical university of Szczecin, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Université de Genève (UNIGE), European Space Agency (ESA), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA), Observatoire de la Côte d'Azur (OCA), Centre National de la Recherche Scientifique (CNRS), Charles University [Prague], Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), DOTA, ONERA, Université Paris Saclay [Châtillon], and ONERA-Université Paris-Saclay
Subjects: 010504 meteorology & atmospheric sciences, Population, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Context (language use), Astrophysics, 01 natural sciences, Impact crater, 0103 physical sciences, 111 Mathematics, observational [Daphne methods], education, 010303 astronomy & astrophysics, asteroids: individual: Daphne, 0105 earth and related environmental sciences, individual: [minor planets, asteroids], Earth and Planetary Astrophysics (astro-ph.EP), Physics, [PHYS]Physics [physics], education.field_of_study, Very Large Telescope, high angular resolution [techniques], techniques: high angular resolution, Astronomy and Astrophysics, asteroids: general, Orbit, Space and Planetary Science, Asteroid, minor planets, Asteroid belt, Satellite, Astrophysics::Earth and Planetary Astrophysics, methods: observational, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], general [minor planets, asteroids], Astrophysics - Earth and Planetary Astrophysics
Abstract: Context. CM-like asteroids (Ch and Cgh classes) are a major population within the broader C-complex, encompassing about 10% of the mass of the main asteroid belt. Their internal structure has been predicted to be homogeneous, based on their compositional similarity as inferred from spectroscopy and numerical modeling of their early thermal evolution. Aims: Here we aim to test this hypothesis by deriving the density of the CM-like asteroid (41) Daphne from detailed modeling of its shape and the orbit of its small satellite. Methods: We observed Daphne and its satellite within our imaging survey with the Very Large Telescope extreme adaptive-optics SPHERE/ZIMPOL camera and complemented this data set with earlier Keck/NIRC2 and VLT/NACO observations. We analyzed the dynamics of the satellite with our Genoid meta-heuristic algorithm. Combining our high-angular resolution images with optical lightcurves and stellar occultations, we determine the spin period, orientation, and 3D shape, using our ADAM shape modeling algorithm. Results: The satellite orbits Daphne on an equatorial, quasi- circular, prograde orbit, like the satellites of many other large main- belt asteroids. The shape model of Daphne reveals several large flat areas that could be large impact craters. The mass determined from this orbit combined with the volume computed from the shape model implies a density for Daphne of 1.77 ¬± 0.26 g cm-3 (3 œÉ). This densityis consistent with a primordial CM-like homogeneous internal structure with some level of macroporosity (‚âà 17%). Conclusions: Based on our analysis of the density of Daphne and 75 other Ch/Cgh-type asteroids gathered from the literature, we conclude that the primordial internal structure of the CM parent bodies was homogeneous. Based on observations made with (1) ESO Telescopes at the La Silla Paranal Observatory under programs http://281.C-5011 (PI Dumas), http://099.D-0098 (SPHERE GTO), and h ttp://199.C-0074(A) (PI Vernazza); and (2) the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.The reduced and deconvolved AO images and the 3D shape model are publicly available at h ttp://observations.lam.fr/astero/ and at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz- bin/qcat?J/A+A/623/A132
Published: 2019

33. Closing the gap between Earth-based and interplanetary mission observations: Vesta seen by VLT/SPHERE

Author: Olivier Witasse, Tadeusz Michalowski, Anna Marciniak, J. Berthier, Benoit Carry, Benoit Neichel, Arthur Vigan, Michael Marsset, E. Podlewska-Gaca, Marin Ferrais, P. Lamy, Laurent Jorda, Pierre Vernazza, Toni Santana-Ros, Bin Yang, Josef Hanus, Matti Viikinkoski, Franck Marchis, Frédéric Vachier, Przemyslaw Bartczak, Christophe Dumas, Mirel Birlan, R. Jl. Fétick, François Colas, Julie Castillo-Rogez, Patrick Michel, Laurent M. Mugnier, Agnieszka Kryszczyńska, M. Pajuelo, Paolo Tanga, H. Le Coroller, Fabrice Cipriani, Thierry Fusco, Alexis Drouard, Mikko Kaasalainen, Grzegorz Dudziński, Emmanuel Jehin, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Astrophysics Research Centre [Belfast] (ARC), Queen's University [Belfast] (QUB), Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), DOTA, ONERA, Université Paris Saclay [Châtillon], ONERA-Université Paris-Saclay, Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Fundació Privada Observatori Esteve Duran, Charles University [Prague], Tampere University of Technology [Tampere] (TUT), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Adam Mickiewicz University in Poznań (UAM), Laboratoire d'Electronique et des Technologies de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Université de Liège, Institut d'Astrophysique et de Géophysique [Liège], Department of Mathematics [Tampere], Astronomical Observatory [Poznan], Observatoire de Haute-Provence (OHP), Institut Pythéas (OSU PYTHEAS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS), Amgen (Europe) GmbH, Galaxies, Etoiles, Physique, Instrumentation (GEPI), PSL Research University (PSL)-PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Pontificia Universidad Católica del Perú (PUCP), Universisty of Szczecin (Szczecin) (Institute of Physics), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Tampere University, Computing Sciences, DOTA, ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Université Paris Saclay (COmUE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Charles University [Prague] (CU), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), University of Szczecin, Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pontificia Universidad Católica del Perú = Pontifical Catholic University of Peru (PUCP), European Space Astronomy Centre (ESAC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Nanophysique Magnétisme et Optoélectronique (LNMO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)
Subjects: Point spread function, [PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Context (language use), techniques: image processing, Astrophysics, 01 natural sciences, Interplanetary mission, Observatory, 0103 physical sciences, 111 Mathematics, 010303 astronomy & astrophysics, Image resolution, 0105 earth and related environmental sciences, Physics, [PHYS]Physics [physics], Earth and Planetary Astrophysics (astro-ph.EP), techniques: high angular resolution, Astronomy and Astrophysics, asteroids: individual: Vesta, Albedo, 13. Climate action, Space and Planetary Science, Asteroid, minor planets, methods: observational, Interplanetary spaceflight, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: International audience; Context. Over the past decades, several interplanetary missions have studied small bodies in situ, leading to major advances in our understanding of their geological and geophysical properties. These missions, however, have had a limited number of targets. Among them, the NASA Dawn mission has characterised in detail the topography and albedo variegation across the surface of asteroid (4) Vesta down to a spatial resolution of 20 m pixel-1 scale. Aims: Here our aim was to determine how much topographic and albedo information can be retrieved from the ground with VLT/SPHERE in the case of Vesta, having a former space mission (Dawn) providing us with the ground truth that can be used as a benchmark. Methods: We observed Vesta with VLT/SPHERE/ZIMPOL as part of our ESO large programme (ID 199.C-0074) at six different epochs, and deconvolved the collected images with a parametric point spread function (PSF). We then compared our images with synthetic views of Vesta generated from the 3D shape model of the Dawn mission, on which we projected Vesta's albedo information. Results: We show that the deconvolution of the VLT/SPHERE images with a parametric PSF allows the retrieval of the main topographic and albedo features present across the surface of Vesta down to a spatial resolution of 20-30 km. Contour extraction shows an accuracy of 1 pixel (3.6 mas). The present study provides the very first quantitative estimate of the accuracy of ground-based adaptive-optics imaging observations of asteroid surfaces. Conclusions: In the case of Vesta, the upcoming generation of 30-40 m telescopes (ELT, TMT, GMT) should in principle be able to resolve all of the main features present across its surface, including the troughs and the north-south crater dichotomy, provided that they operate at the diffraction limit. Reduced images of Table A.1 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/623/A6Based on observations made with ESO Telescopes at the Paranal Observatory under programme ID 199.C-0074 (PI: P. Vernazza).
Published: 2019

34. (16) Psyche: A mesosiderite-like asteroid?

Author: Tadeusz Michalowski, P. Bartczak, J. Grice, Brian D. Warner, Christophe Dumas, Frédéric Vachier, Laurent Jorda, Josef Hanus, Olivier Witasse, Alexis Drouard, E. Podlewska-Gaca, Fabrice Cipriani, Romain Fétick, François Colas, Julie Castillo-Rogez, Philippe Lamy, F. Marchis, Marin Ferrais, Emmanuel Jehin, Jérôme Berthier, Josef Ďurech, P. Michel, A. Marciniak, Arthur Vigan, Pierre Vernazza, H. Le Coroller, Thierry Fusco, Bin Yang, Michael Marsset, Mirel Birlan, Toni Santana-Ros, Benoit Carry, Matti Viikinkoski, Agnieszka Kryszczyńska, Mikko Kaasalainen, K. Tazhenova, M. Pajuelo, Paolo Tanga, Tampere University of Technology [Tampere] (TUT), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Astronomical Institute of Charles University, Charles University [Prague] (CU), Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Astrophysics Research Centre [Belfast] (ARC), Queen's University [Belfast] (QUB), Search for Extraterrestrial Intelligence Institute (SETI), DOTA, ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Université Paris Saclay (COmUE), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Faculty of Physics [Poznań], Adam Mickiewicz University in Poznań (UAM), TMT International Observatory, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Open University (School of Physical Sciences), Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Pontificia Universidad Católica del Perú = Pontifical Catholic University of Peru (PUCP), University of Szczecin, Center for Solar System Studies (CS3), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), TMT Observatory, European Space Agency (ESA), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), and Pontificia Universidad Católica del Perú (PUCP)
Subjects: Physics, Earth and Planetary Astrophysics (astro-ph.EP), 010504 meteorology & atmospheric sciences, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Spectral properties, FOS: Physical sciences, Astronomy and Astrophysics, Context (language use), Astrophysics, 01 natural sciences, Parent body, Psyche, Mesosiderite, Meteorite, Space and Planetary Science, Asteroid, [SDU]Sciences of the Universe [physics], 0103 physical sciences, Hill sphere, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract: Asteroid (16) Psyche is the target of the NASA Psyche mission. It is considered one of the few main-belt bodies that could be an exposed proto-planetary metallic core and that would thus be related to iron meteorites. Such an association is however challenged by both its near- and mid-infrared spectral properties and the reported estimates of its density. Here, we aim to refine the density of (16) Psyche to set further constraints on its bulk composition and determine its potential meteoritic analog. We observed (16) Psyche with ESO VLT/SPHERE/ZIMPOL as part of our large program (ID 199.C-0074). We used the high angular resolution of these observations to refine Psyche's three-dimensional (3D) shape model and subsequently its density when combined with the most recent mass estimates. In addition, we searched for potential companions around the asteroid. We derived a bulk density of 3.99\,$\pm$\,0.26\,g$\cdot$cm$^{-3}$ for Psyche. While such density is incompatible at the 3-sigma level with any iron meteorites ($\sim$7.8\,g$\cdot$cm$^{-3}$), it appears fully consistent with that of stony-iron meteorites such as mesosiderites (density $\sim$4.25\,$\cdot$cm$^{-3}$). In addition, we found no satellite in our images and set an upper limit on the diameter of any non-detected satellite of 1460\,$\pm$\,200}\,m at 150\,km from Psyche (0.2\%\,$\times$\,R$_{Hill}$, the Hill radius) and 800\,$\pm$\,200\,m at 2,000\,km (3\%\,$\times$\,$R_{Hill}$). Considering that the visible and near-infrared spectral properties of mesosiderites are similar to those of Psyche, there is merit to a long-published initial hypothesis that Psyche could be a plausible candidate parent body for mesosiderites., 16 pages
Published: 2018

35. Photometry of asteroids (5141), (43032), (85953), (259221), and (363599) observed at Pic du Midi Observatory

Author: A. Sonka, François Colas, B. A. Dumitru, Mirel Birlan, D. A. Nedelcu, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Astronomical Observatory 'Admiral Vasile Urseanu', Bucharest Municipal Museum, L2EP - Équipe Réseaux, Laboratoire d’Électrotechnique et d’Électronique de Puissance - ULR 2697 (L2EP), Centrale Lille-Haute Etude d'Ingénieurs-Université de Lille-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)-Centrale Lille-Haute Etude d'Ingénieurs-Université de Lille-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM), Institut de Mécanique Céleste et de Calcul des Ephémérides [IMCCE], Laboratoire d'Électrotechnique et d'Électronique de Puissance (L2EP) - ULR 2697, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Centrale Lille-Université de Lille-Arts et Métiers Sciences et Technologies, HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-JUNIA (JUNIA), Université catholique de Lille (UCL)-Université catholique de Lille (UCL)-Centrale Lille-Université de Lille-Arts et Métiers Sciences et Technologies, and Université catholique de Lille (UCL)-Université catholique de Lille (UCL)
Subjects: asteroids, Daytime, 010504 meteorology & atmospheric sciences, photometry, FOS: Physical sciences, 01 natural sciences, Observatory, 0103 physical sciences, Perseids, near earth asteroids, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Near-Earth object, Meteoroid, NEAs, Astronomy, colors, Pic du Midi, Astronomy and Astrophysics, Light curve, Photometry (astronomy), Space and Planetary Science, Asteroid, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Geology, Astrophysics - Earth and Planetary Astrophysics
Abstract: These are the first results of an observational program devoted to the complete physical data of asteroids that could produce or feed meteoroid streams. Our results are based on the optical observation at Pic du Midi observatory in April 6-7, 2016 and January 17-18, 2018. We will present the light curve of asteroid (259221) 2003 BA21, associated with Daytime Sextantids (221 DSX) and November theta Aurigids (390 THA); the light curves and colors of asteroid (363599) 2004 FG11, associated with Daytime zeta Perseids (172 ZPE) as well as g-r and g-i; and the corresponding reflectances for the (85953) 1999 FK21, associated with Daytime eta Sagittariids (100 XSA). We will also present the colors for two additional objects, namely, (5141) Tachibana and (43032) 1999 VR26., Comment: 7 pages 6 figures
Published: 2018

36. Probing the use of spectroscopy to determine the meteoritic analogues of meteors

Author: J. Gattacceca, Sylvain Bouley, Pierre Vernazza, Chiara Marmo, Rainer Oefele, Alexis Drouard, Arne Meindl, B. Zanda, Jeremie Vaubaillon, Fabian Zander, Tobias Hermann, Mirel Birlan, Martin Eberhart, F. Colas, F. Zamkotsian, Laurent Jorda, Stefan Loehle, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Institut für Raumfahrtsysteme (IRS), Universität Stuttgart [Stuttgart], Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Muséum national d'Histoire naturelle (MNHN), Astronomical Institute of Romanian Academy, Romanian Academy, Géosciences Paris Sud (GEOPS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)
Subjects: [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Context (language use), Astrophysics, 010502 geochemistry & geophysics, 01 natural sciences, meteorites, Astrobiology, Recovery rate, 0103 physical sciences, meteors, Spectroscopy, meteoroids, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Meteoroid, Astronomy and Astrophysics, Planetary science, Camera network, Meteorite, Space and Planetary Science, Asteroid, spectroscopic [techniques], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], techniques: spectroscopic, Astrophysics - Earth and Planetary Astrophysics
Abstract: Context. Determining the source regions of meteorites is one of the major goals of current research in planetary science. Whereas asteroid observations are currently unable to pinpoint the source regions of most meteorite classes, observations of meteors with camera networks and the subsequent recovery of the meteorite may help make progress on this question. The main caveat of such an approach, however, is that the recovery rate of meteorite falls is low ( Aims. Spectroscopic observations of incoming bolides may have the potential to mitigate this problem by classifying the incoming meteoritic material. Methods. To probe the use of spectroscopy to determine the meteoritic analogues of incoming bolides, we collected emission spectra in the visible range (320–880 nm) of five meteorite types (H, L, LL, CM, and eucrite) acquired in atmospheric entry-like conditions in a plasma wind tunnel at the Institute of Space Systems (IRS) at the University of Stuttgart (Germany). A detailed spectral analysis including a systematic line identification and mass ratio determinations (Mg/Fe, Na/Fe) was subsequently performed on all spectra. Results. It appears that spectroscopy, via a simple line identification, allows us to distinguish the three main meteorite classes (chondrites, achondrites and irons) but it does not have the potential to distinguish for example an H chondrite from a CM chondrite. Conclusions. The source location within the main belt of the different meteorite classes (H, L, LL, CM, CI, etc.) should continue to be investigated via fireball observation networks. Spectroscopy of incoming bolides only marginally helps precisely classify the incoming material (iron meteorites only). To reach a statistically significant sample of recovered meteorites along with accurate orbits (>100) within a reasonable time frame (10–20 years), the optimal solution may be the spatial extension of existing fireball observation networks.
Published: 2018

37. Spectral properties of binary asteroids

Author: Jérôme Berthier, Richard P. Binzel, Francesca E. DeMeo, M. Pajuelo, Benoit Carry, Mirel Birlan, Pontificia Universidad Católica del Perú (PUCP), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Astronomical Institute of Romanian Academy, Romanian Academy, Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), Pontificia Universidad Católica del Perú = Pontifical Catholic University of Peru (PUCP), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, meteoroids-minor planets, 010504 meteorology & atmospheric sciences, Meteoroid, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Spectral properties, Astronomy, Binary number, Astronomy and Astrophysics, 01 natural sciences, Methods observational, asteroids: general, Meteorite, surveys-meteorites, Space and Planetary Science, Asteroid, 0103 physical sciences, methods: observational, meteors, 10. No inequality, 010303 astronomy & astrophysics, techniques: spectroscopic, 0105 earth and related environmental sciences
Abstract: International audience; We present the first attempt to characterize the distribution of taxonomic class among the population of binary asteroids (15 per cent of all small asteroids). For that, an analysis of 0.8-2.5 μm near-infrared spectra obtained with the SpeX instrument on the NASA/IRTF is presented. Taxonomic class and meteorite analogue is determined for each target, increasing the sample of binary asteroids with known taxonomy by 21 per cent. Most binary systems are bound in the S, X, and C classes, followed by Q and V types. The rate of binary systems in each taxonomic class agrees within uncertainty with the background population of small near-Earth objects and inner main belt asteroids, but for the C types which are under-represented among binaries.
Published: 2018

38. The impact crater at the origin of the Julia family detected with VLT/SPHERE?

Author: Matti Viikinkoski, Toni Santana-Ros, M. Pajuelo, Paolo Tanga, Miroslav Brož, Emmanuel Jehin, Josef Hanus, Zouhair Benkhaldoun, F. Vachier, E. Podlewska-Gaca, Fabrice Cipriani, Bin Yang, Erik Asphaug, Laurent Jorda, Mikko Kaasalainen, Pierre Vernazza, Julie Castillo-Rogez, P. Lamy, Alexis Drouard, Grzegorz Dudziński, Josef Ďurech, P. Michel, Olivier Witasse, Michael Marsset, P. Ševeček, Michaël Gillon, Arthur Vigan, Agnieszka Kryszczyńska, F. Marchis, Jérôme Berthier, P. Bartczak, Thierry Fusco, Benoit Carry, H. Le Coroller, Mirel Birlan, A. Marciniak, Christophe Dumas, Romain Fétick, Tadeusz Michalowski, Derek C. Richardson, Brian D. Warner, F. Colas, Marin Ferrais, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Astronomical Institute of Charles University, Charles University [Prague] (CU), Department of Mathematics [Tampere], Tampere University of Technology [Tampere] (TUT), Astrophysics Research Centre [Belfast] (ARC), Queen's University [Belfast] (QUB), Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Search for Extraterrestrial Intelligence Institute (SETI), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), DOTA, ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Université Paris Saclay (COmUE), Astronomical Observatory [Poznan], Adam Mickiewicz University in Poznań (UAM), University of Szczecin, Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), TMT Observatory, Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Pontificia Universidad Católica del Perú (PUCP), Center for Solar System Studies (CS3), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), ASU School of Earth and Space Exploration (SESE), Arizona State University [Tempe] (ASU), University of Maryland [College Park], University of Maryland System, Université Cadi Ayyad [Marrakech] (UCA), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA), TMT International Observatory, Pontificia Universidad Católica del Perú = Pontifical Catholic University of Peru (PUCP), Tampere University, and Mathematics
Subjects: Physics, 010504 meteorology & atmospheric sciences, Collisional family, techniques: high angular resolution, asteroids: individual: (89) Julia, Astronomy and Astrophysics, Context (language use), Astrophysics, Asteroid family, 01 natural sciences, Parent body, methods: numerical, Impact crater, Space and Planetary Science, Asteroid, Observatory, 0103 physical sciences, 111 Mathematics, minor planets, methods: observational, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Interplanetary spaceflight, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: Context.The vast majority of the geophysical and geological constraints (e.g., internal structure, cratering history) for main-belt asteroids have so far been obtained via dedicated interplanetary missions (e.g., ESA Rosetta, NASA Dawn). The high angular resolution of SPHERE/ZIMPOL, the new-generation visible adaptive-optics camera at ESO VLT, implies that these science objectives can now be investigated from the ground for a large fraction ofD≥ 100 km main-belt asteroids. The sharp images acquired by this instrument can be used to accurately constrain the shape and thus volume of these bodies (hence density when combined with mass estimates) and to characterize the distribution and topography ofD≥ 30 km craters across their surfaces.Aims.Here, via several complementary approaches, we evaluated the recently proposed hypothesis that the S-type asteroid (89) Julia is the parent body of a small compact asteroid family that formed via a cratering collisional event.Methods.We observed (89) Julia with VLT/SPHERE/ZIMPOL throughout its rotation, derived its 3D shape, and performed a reconnaissance and characterization of the largest craters. We also performed numerical simulations to first confirm the existence of the Julia family and to determine its age and the size of the impact crater at its origin. Finally, we utilized the images/3D shape in an attempt to identify the origin location of the small collisional family.Results.On the one hand, our VLT/SPHERE observations reveal the presence of a large crater (D~ 75 km) in Julia’s southern hemisphere. On the other hand, our numerical simulations suggest that (89) Julia was impacted 30–120 Myrs ago by aD~ 8 km asteroid, thereby creating aD≥ 60 km impact crater at the surface of Julia. Given the small size of the impactor, the obliquity of Julia and the particular orientation of the family in the (a,i) space, the imaged impact crater is likely to be the origin of the family.Conclusions.New doors into ground-based asteroid exploration, namely, geophysics and geology, are being opened thanks to the unique capabilities of VLT/SPHERE. Also, the present work may represent the beginning of a new era of asteroid-family studies. In the fields of geophysics, geology, and asteroid family studies, the future will only get brighter with the forthcoming arrival of 30–40 m class telescopes like ELT, TMT, and GMT.
Published: 2018
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39. Search for horizontal and vertical variations of CO in the day and night side lower mesosphere of Venus from CSHELL/IRTF 4.53μm observations

Author: Thérèse Encrenaz, Emmanuel Marcq, Jean-Loup Bertaux, Thomas Widemann, Emmanuel Lellouch, Mirel Birlan, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Carbon Monoxide, 010504 meteorology & atmospheric sciences, biology, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Infrared Spectroscopy, Planetary Atmospheres, Astronomy and Astrophysics, Scale height, Venus, Atmospheric sciences, biology.organism_classification, 01 natural sciences, Latitude, Aerosol, Mesosphere, Atmosphere, Altitude, 13. Climate action, Space and Planetary Science, 0103 physical sciences, Mixing ratio, Environmental science, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: High-resolution ( R ~ 43 , 000 ) spectroscopic observations of both day and night sides of Venus were acquired using CSHELL at IRTF between 2202 and 2207 cm − 1 (4.53– 4.54 μ m ) during the latest maximal eastern and western elongations of Venus in two four-nights observing runs in August 2012 and November 2013. Their purpose was to investigate the effect of the recent (from 2007 onwards) decrease of sulfur dioxide (SO2) at the cloud top level on the spatial distribution of carbon monoxide (CO), since both species are involved in the mesospheric photochemical cycles. Observations of neighboring CO2 lines are fully consistent with the previously determined aerosol scale height in the 68–74 km range. We could therefore determine CO mixing ratio on both day and night sides of Venus, taking into account both scattered solar and thermal components, as well as the overlying CO dayglow on the day side. CO spatial distribution is mostly unchanged compared to previous measurements, ranging from 25 ppmv to 45 ppmv at 70 km. The scattered solar component reveals an increase in CO with increasing altitude with a scale height of ( 5 ± 0.5 ) km between 70 and 76 km. Horizontal variability is found to be weak, with a possible increase towards higher latitudes on the day side of about 10 ppmv. Yet the accuracy of our absolute values of CO mixing ratio is limited by several assumptions, and we cannot rule out that some of the variability we measure for CO could alternatively be explained by other changes occurring in the Venusian atmosphere, e.g. changes in both dT/dz and aerosol scale height.
Published: 2015

40. Mining the ESO WFI and INT WFC archives for known Near Earth Asteroids. Mega-Precovery software

Author: M. Constantinescu, T. Badescu, C. Opriseanu, O. Suciu, A. Tudorica, Mirel Birlan, D. Vidican, F. Char, Marcel Popescu, Alin Razvan Paraschiv, Ovidiu Vaduvescu, D. Lacatus, Mihaela Badea, Iulia M. Comsa, and A. Sonka
Subjects: Near-Earth object, 010308 nuclear & particles physics, business.industry, Potentially hazardous object, Astronomy, Astronomy and Astrophysics, Astrometry, 01 natural sciences, Wide field, Precovery, Software, Space and Planetary Science, Asteroid, 0103 physical sciences, business, 010303 astronomy & astrophysics, Minor planet, Geology
Abstract: The ESO/MPG WFI and the INT WFC wide field archives comprising 330 000 images were mined to search for serendip-itous encounters of known Near Earth Asteroids (NEAs) and Potentially Hazardous Asteroids (PHAs). A total of 152 as-teroids (44 PHAs and 108 other NEAs) were identified using the PRECOVERY software, their astrometry being measured on 761 images and sent to the Minor Planet Centre. Both recoveries and precoveries were reported, including prolonged orbital arcs for 18 precovered objects and 10 recoveries. We analyze all new opposition data by comparing the orbits fitted before and after including our contributions. We conclude the paper presenting “Mega-Precovery”, a new online service focused on data mining of many instrument archives simultaneously for one or a few given asteroids. A total of 28 instrument archives have been made available for mining using this tool, adding together about 2.5 million images forming the “Mega-Archive”
Published: 2013

41. COMPOSITIONAL HOMOGENEITY OF CM PARENT BODIES

Author: Francesca E. DeMeo, Michael Marsset, Takahiro Hiroi, Edward A. Cloutis, P. G. Beck, Mirel Birlan, R. P. Binzel, Pierre Vernazza, C. Dumas, Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Department of Geography [Winnipeg], University of Winnipeg, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Centre de Formation et de Recherche sur les Environnements Méditérranéens (CEFREM), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Brown University, Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), and Université de Perpignan Via Domitia (UPVD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Solar System, 010504 meteorology & atmospheric sciences, Meteoroid, data analysis – methods: laboratory: solid state – methods: observational – minor planets, asteroids: general – techniques: spectroscopic [meteorites, meteors, meteoroids – methods], Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Regolith, Parent body, Grain size, Meteorite, 13. Climate action, Space and Planetary Science, Asteroid, Chondrite, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: CM chondrites are the most common type of hydrated meteorites, making up ∼1.5% of all falls. Whereas most CM chondrites experienced only low-temperature (∼0°C–120°C) aqueous alteration, the existence of a small fraction of CM chondrites that suffered both hydration and heating complicates our understanding of the early thermal evolution of the CM parent body(ies). Here, we provide new constraints on the collisional and thermal history of CM-like bodies from a comparison between newly acquired spectral measurements of main-belt Ch/Cgh-type asteroids (70 objects) and existing laboratory spectral measurements of CM chondrites. It first appears that the spectral variation observed among CM-like bodies is essentially due to variations in the average regolith grain size. Second, the spectral properties of the vast majority (unheated) of CM chondrites resemble both the surfaces and the interiors of CM-like bodies, implying a “low” temperature ( 100 km)—supposedly primordial—Ch/ Cgh-type main-belt asteroids likely expose the interiors of the primordial CM parent bodies, a possible consequence of impacts by small asteroids (D < 10 km) in the early solar system. The MIT component of this work is supported by NASA grant 09-NEOO009-0001, and by the National Science Foundation under grants Nos. 0506716 and 0907766. F.E.D. acknowledges support from NASA under grant No. NNX12AL26G issued through the Planetary Astronomy Program. E.A.C. thanks the Canada Foundation for Innovation, the Manitoba Research Innovations Fund, the Canadian Space Agency, the University of Winnipeg, and the Natural Sciences and Engineering Research Council of Canada for supporting the establishment and operation of the University of Winnipeg's Planetary Spectrophotometer Facility and this study. http://iopscience.iop.org/article/10.3847/0004-6256/152/3/54/meta
Published: 2016

42. Compositional characterisation of the Themis family

Author: Richard P. Binzel, Christophe Dumas, Francesca E. DeMeo, Michael Marsset, Pierre Vernazza, Marcel Popescu, Mirel Birlan, Julien Milli, Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Centre de Formation et de Recherche sur les Environnements Méditérranéens (CEFREM), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), and Université de Perpignan Via Domitia (UPVD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Earth and Planetary Astrophysics (astro-ph.EP), 010504 meteorology & atmospheric sciences, Meteoroid, Interplanetary medium, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Astrobiology, Planetary science, Meteorite, Space and Planetary Science, Asteroid, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract: Context. It has recently been proposed that the surface composition of icy main-belt asteroids (B-,C-,Cb-,Cg-,P-,and D-types) may be consistent with that of chondritic porous interplanetary dust particles (CPIDPs). Aims. In the light of this new association, we re-examine the surface composition of a sample of asteroids belonging to the Themis family in order to place new constraints on the formation and evolution of its parent body. Methods. We acquired NIR spectral data for 15 members of the Themis family and complemented this dataset with existing spectra in the visible and mid-infrared ranges to perform a thorough analysis of the composition of the family. Assuming end-member minerals and particle sizes (4Myr after CAIs) so that only moderate internal heating occurred in its interior, preventing aqueous alteration of the outer shell., 9 pages, 5 figures, accepted for publication in A&A
Published: 2016

43. EURONEAR—Recovery, follow-up and discovery of NEAs and MBAs using large field 1–2m telescopes

Author: D. Dumitru, A. Sonka, David Asher, Iulia M. Comsa, Javier Licandro, T. Badescu, A. Nedelcu, Eduardo Unda-Sanzana, C. Vancea, A. Barr, R. Toma, J. L. Ortiz, D. Vidican, Ovidiu Vaduvescu, F. Pozo, Mirel Birlan, M. Constantinescu, M. Badea, Marcel Popescu, C. Opriseanu, A. Tudorica, Isaac Newton Group of Telescopes, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Groupe Astrométrie et Planétologie (GAP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Astronomical Institute of the Romanian Academy, Bucharest, Bonn Cologne Graduate School of Physics and Astronomy, Astronomical Observatory 'Admiral Vasile Urseanu', Instituto de Astronomia, Universidad Catolica del Norte, Armagh Observatory, College Hill, Instituto de Astrofísica de Canarias (IAC), Instituto de Astrofisica de Andalucia, CSIC (IAA), Astroclubul Bucuresti, Department of Physics, University of Bucharest, Rheinische Friedrich-Wilhelms-Universität Bonn, and Faculty of Mathematics and Informatics, Babes-Bolyai University
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), Orbital elements, Physics, Near-Earth object, media_common.quotation_subject, FOS: Physical sciences, Astronomy, Astronomy and Astrophysics, Astrometry, Astrophysics, law.invention, Telescope, Space and Planetary Science, Asteroid, Sky, law, Evaluation methods, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics, media_common
Abstract: We report on the follow-up and recovery of 100 program NEAs, PHAs and VIs using the ESO/MPG 2.2m, Swope 1m and INT 2.5m telescopes equipped with large field cameras. The 127 fields observed during 11 nights covered 29 square degrees. Using these data, we present the incidental survey work which includes 558 known MBAs and 628 unknown moving objects mostly consistent with MBAs from which 58 objects became official discoveries. We planned the runs using six criteria and four servers which focus mostly on faint and poorly observed objects in need of confirmation, follow-up and recovery. We followed 62 faint NEAs within one month after discovery and we recovered 10 faint NEAs having big uncertainties at their second or later opposition. Using the INT we eliminated 4 PHA candidates and VIs. We observed in total 1,286 moving objects and we reported more than 10,000 positions. All data were reduced by the members of our network in a team effort, and reported promptly to the MPC. The positions of the program NEAs were published in 27 MPC and MPEC references and used to improve their orbits. The O-C residuals for known MBAs and program NEAs are smallest for the ESO/MPG and Swope and about four times larger for the INT whose field is more distorted. The incidental survey allowed us to study statistics of the MBA and NEA populations observable today with 1--2m facilities. We calculate preliminary orbits for all unknown objects, classifying them as official discoveries, later identifications and unknown outstanding objects. The orbital elements a, e, i calculated by FIND_ORB software for the official discoveries and later identified objects are very similar with the published elements which take into account longer observational arcs; thus preliminary orbits were used in statistics for the whole unknown dataset. (CONTINUED), Accepted in Planetary and Space Science (Aug 2011)
Published: 2011

44. Spectral properties of (854) Frostia, (1333) Cevenola and (3623) Chaplin

Author: Franck Marchis, Pascal Descamps, S. Merouane, Mirel Birlan, Jérôme Berthier, Dan Alin Nedelcu, and Marcel Popescu
Subjects: Physics, Observational techniques, Infrared telescope, Astronomy, Astronomy and Astrophysics, Light curve, law.invention, Photometry (optics), Space and Planetary Science, law, Asteroid, Planet, Radar, Spectroscopy
Abstract: Near-infrared spectroscopy can play a key role in establishing the mineralogical composition of objects and supporting other physical data obtained by complementary observational techniques such as adaptive optics, radar and photometry. The objective of our survey was asteroids that present large variations in their light curves. We report observations for asteroids (854) Frostia, (1333) Cevenola and (3623) Chaplin carried out in the 0.8-2.5 μm spectral range using SpeX/Infrared Telescope Facility (IRTF) in LowRes mode. The spectral modelling of these asteroids gives new insights into these peculiar objects in the main belt. (854) Frostia is a V-type asteroid, and its spectral properties are similar to those of basalts. The most probable mineralogical solution Wo 8 Fs 43 En 49 was calculated for Frostia. (1333) Cevenola was estimated to have an Sq spectral type, in agreement with its membership of the Eunomia family. (3623) Chaplin is an S-type asteroid, in agreement with the taxonomic type of the Koronis family.
Published: 2011

45. Earth encounters as the origin of fresh surfaces on near-Earth asteroids

Author: Francesca E. DeMeo, Sihane Merouane, Cristina A. Thomas, Alessandro Morbidelli, Schelte J. Bus, Alan T. Tokunaga, Pierre Vernazza, Andrew S. Rivkin, Richard P. Binzel, Mirel Birlan, Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, and Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Solar System, Multidisciplinary, Near-Earth object, 010504 meteorology & atmospheric sciences, 01 natural sciences, Space weathering, Astrobiology, Meteorite, 13. Climate action, Chondrite, Asteroid, 0103 physical sciences, Terrestrial planet, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Ordinary chondrite
Abstract: The 'ordinary chondrite problem' has been a factor in Solar System astronomy for three decades. It refers to the apparent anomaly that whereas about 80% of the meteorites falling to Earth are 'ordinary chondrites', they are rare among asteroids. The usual explanation is that 'space weathering' processes alter ordinary chondrite surfaces, producing reddened 'S-type' asteroids. A mystery remains, though, in the shape of a rare class of asteroids, the Q-types. These are found only near the Earth, and they do display 'fresh' spectral matches to ordinary chondrites. Now the combination of a new data set of 95 asteroid spectra with their detailed orbital histories shows that all Q-type asteroids have recently passed close to Earth at least within the lunar distance. Thus tidal stresses or seismic shaking during these encounters may have exposed new unweathered material on the surface. Intriguingly a test of this hypothesis may be at hand: 99942 Apophis, a potentially Earth-threatening asteroid currently displaying 'weathered' spectral colours, is due to pass within six orbital radii of Earth in 2029. It is predicted that it will experience a seismic 'fresh shake', which should expose new unreddened material on the surface. Telescopic measurements of asteroids' colours rarely match laboratory reflectance spectra of meteorites owing to a 'space weathering' process that rapidly reddens asteroid surfaces. 'Unweathered' asteroids, however, with spectra matching ordinary chondrite meteorites, are seen only among small bodies with orbits that cross inside the orbits of Mars and Earth. Such unweathered asteroids are now shown to have experienced orbital intersections closer than the Earth–Moon distance within the past half-million years. Telescopic measurements of asteroids’ colours rarely match laboratory reflectance spectra of meteorites owing to a ‘space weathering’1,2 process that rapidly3 reddens asteroid surfaces in less than 106 years. ‘Unweathered’ asteroids (those having spectra matching the most commonly falling ordinary chondrite meteorites), however, are seen among small bodies the orbits of which cross inside Mars and the Earth. Various explanations have been proposed for the origin of these fresh surface colours, ranging from collisions4 to planetary encounters5. Less reddened asteroids seem to cross most deeply into the terrestrial planet region, strengthening6 the evidence for the planetary-encounter theory5, but encounter details within 106 years remain to be shown. Here we report that asteroids displaying unweathered spectra (so-called ‘Q-types’7) have experienced orbital intersections closer than the Earth–Moon distance within the past 5 × 105 years. These Q-type asteroids are not currently found among asteroids showing no evidence of recent close planetary encounters. Our results substantiate previous work5: tidal stress8, strong enough to disturb and expose unweathered surface grains, is the most likely dominant short-term asteroid resurfacing process. Although the seismology details are yet to be worked out, the identification of rapid physical processes that can produce both fresh and weathered asteroid surfaces resolves the decades-long9 puzzle of the difference in colour of asteroids and meteorites.
Published: 2010

46. EURONEAR: First results

Author: A. Sonka, Ovidiu Vaduvescu, Mirel Birlan, F. Colas, A. Nedelcu, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Groupe Astrométrie et Planétologie (GAP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Instituto de Astronomia, Universidad Catolica del Norte, Astronomical Observatory 'Admiral Vasile Urseanu', and Astronomical Institute of the Romanian Academy, Bucharest
Subjects: Physics, Near-Earth object, Potentially hazardous object, Astronomy, Astronomy and Astrophysics, Astrometry, Astrobiology, law.invention, Telescope, Photometry (optics), Space and Planetary Science, law, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Minor planet
Abstract: International audience; The European Near Earth Asteroid Research (EURONEAR) is a project which envisions to build a coordinated network which will follow-up and recover potentially hazardous asteroids (PHAs) and near earth asteroids (NEAs). We aim to include in EURONEAR two automated 1 m telescopes located in Chile and Europe, in addition to other non-permanent facilities. Astrometry will be the main aim of the project in order to secure and follow-up newly discovered NEAs, also to recover PHAs at their second or following oppositions, while photometry of bright PHAs will bring information on their physical properties. In this paper, first we review briefly the existent and past NEAs programs. Next, we include the results obtained in 2006 from three observing runs at Pic du Midi using the 1 m telescope, Haute-Provence employing the 1.2 m telescope, and Bucharest using a small 23 cm telescope. These add a total of 153 positions for 16 PHAs and NEAs, which were accepted by Minor Planet Center. Recently, a 1 m telescope was allocated by ESO in La Silla to be automated and used as the Southern dedicated facility by EURONEAR.
Published: 2008

47. Spectral properties of nine M-type asteroids

Author: Mirel Birlan, Pierre Vernazza, Dan Alin Nedelcu, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Astronomical Institute of Romanian Academy, Romanian Academy, Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)
Subjects: asteroids, Physics, 010504 meteorology & atmospheric sciences, Absorption spectroscopy, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Scattering, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astronomy, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Spectral line, Meteorite, Space and Planetary Science, Asteroid, Planet, 0103 physical sciences, minor planets, Prism, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Visible spectrum
Abstract: Reproduced with permission. Copyright ESO. Article published by EDP Sciences and available at http://www.aanda.org.; International audience; Aims. We present spectroscopic results for nine M-type asteroids (325 Heidelberga, 497 Iva, 558 Carmen, 687 Tinette, 766 Moguntia, 860 Ursina, 909 Ulla, 1280 Baillauda, and 1564 Srbija) in the 0.8−2.5 μm spectral region. One visible spectrum is also presented for the asteroid 497 Iva. These asteroids were observed during several runs between 2003 and 2007, and the main goal was to investigate the NIR spectral region of M-type asteroids. Methods. The data was obtained with SpeX/IRTF in Prism mode and Dolores/TNG in LR-B mode. Spectral analysis was performed by comparing the M-type spectra and the meteorite ones (χ2 approach) and the Modified Gaussian Model. Results. With one exception, the asteroids present positive slopes of the spectra, with no absorption features, in good agreement with the spectra of metallic meteorites. The analysis of the asteroid 766 Moguntia was done by means of χ2, MGM techniques, and the Shkuratov scattering law. We conclude that the mineralogy is dominated by olivine. Its NIR spectrum is similar to those of CO/CV meteorites.
Published: 2007

48. Characterization of (357439) 2004 BL86 on its close approach to Earth in 2015

Author: A. Sonka, Marcel Popescu, Dan Alin Nedelcu, F. Stevance, Vlad Turcu, Dan Moldovan, B. A. Dumitru, Alexandru Pop, Ovidiu Vaduvescu, L. Mircea, Mirel Birlan, P. Rocher, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Astronomical Institute of Romanian Academy, Romanian Academy, Astronomical Observatory Cluj-Napoca, Isaac Newton Group of Telescopes, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)
Subjects: Rotation period, Physics, [PHYS]Physics [physics], 010504 meteorology & atmospheric sciences, Newtonian telescope, Potentially hazardous object, Astronomy, Astronomy and Astrophysics, Context (language use), Astrophysics, Light curve, 01 natural sciences, Parent body, law.invention, Meteorite, 13. Climate action, Space and Planetary Science, Asteroid, law, [SDU]Sciences of the Universe [physics], 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: Context. The potentially hazardous asteroid (PHA) (357439) 2004 BL86 grazed Earth on January 26, 2015 at a distance of about 1.2 million km. This favorable geometry allowed observing it to derive its physical and dynamical parameters. (357439) 2004 BL86 was previously estimated to be a 500-m body. We study it also considering possible mechanisms that might mitigate the effect of asteroids that might become dangerous for Earth. Aims. Physical and dynamical investigations of this peculiar object were performed to be able to characterize this object. Methods. We used spectral observations obtained in the visible (V) using the Isaac Newton Telescope and in the near-infrared (NIR) using the InfraRed Telescope Facility. A complementary photometric survey during two nights was also provided by the Astronomical Observatory Cluj-Feleacu station in Romania. We anlyzed the data using reliable mathematical tools that were previously published under the acronym M4AST.Results. VNIR spectral observations classify (357439) 2004 BL86 as V-type asteroid. The mineralogical analysis reveals its similarities to howardite-eucrite-diogenite meteorites. The band analysis reveals that the object is more similar to a eucritic and howarditic composition, and that it originated from the crust of a large parent body. The analysis yields a mineralogical solution of Wo17 Fs39 with an error bar of 4%. Based on the average value of the thermal albedo for V-type objects, its diameter was re-estimated to a value of 290 ± 30 m. The dynamical analysis shows a chaotical behavior of (357439) 2004 BL86. The statistics on meteorite falls show that (357439) 2004 BL86 does not appear to significantly contribute to the current howardite-eucrite-diogenite meteorite flux. For the two photometrical observing runs the following values of the rotational period and peak-to-peak amplitude were estimated for the light curves: 2.637 ± 0.024 h, 0.105 ± 0.007 mag, and 2.616 ± 0.061 h, 0.109 ± 0.018 mag, respectively.
Published: 2015

49. INTERPLANETARY DUST PARTICLES AS SAMPLES OF ICY ASTEROIDS

Author: Michael Marsset, Pierre Vernazza, Richard P. Binzel, Brigitte Zanda, Sihane Merouane, Zahia Djouadi, Mirel Birlan, Christophe Dumas, Rosario Brunetto, Francesca E. DeMeo, Olivier Mousis, Pierre Beck, Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Centre de Formation et de Recherche sur les Environnements Méditérranéens (CEFREM), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université de Perpignan Via Domitia (UPVD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)
Subjects: Physics, Solar System, 010504 meteorology & atmospheric sciences, Meteoroid, Astronomy, Interplanetary medium, Extraterrestrial materials, Astronomy and Astrophysics, 01 natural sciences, Astrobiology, Interplanetary dust cloud, Meteorite, Space and Planetary Science, Asteroid, [SDU]Sciences of the Universe [physics], 0103 physical sciences, Asteroid belt, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: International audience; Meteorites have long been considered as reflections of the compositional diversity of main belt asteroids and consequently they have been used to decipher their origin, formation, and evolution. However, while some meteorites are known to sample the surfaces of metallic, rocky and hydrated asteroids (about one-third of the mass of the belt), the low-density icy asteroids (C-, P-, and D-types), representing the rest of the main belt, appear to be unsampled in our meteorite collections. Here we provide conclusive evidence that the surface compositions of these icy bodies are compatible with those of the most common extraterrestrial materials (by mass), namely anhydrous interplanetary dust particles (IDPs). Given that these particles are quite different from known meteorites, it follows that the composition of the asteroid belt consists largely of more friable material not well represented by the cohesive meteorites in our collections. In the light of our current understanding of the early dynamical evolution of the solar system, meteorites likely sample bodies formed in the inner region of the solar system (0.5-4AU) whereas chondritic porous IDPs sample bodies that formed in the outer region (\textgreater5 AU).
Published: 2015

50. Taxonomy of Centaurs and Trans-Neptunian Objects

Author: Irina Belskaya, Marcello Fulchignoni, Mirel Birlan, M. A. Barucci, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institute of Astronomy [Kharkiv], V.N. Karazin Kharkiv National University (KhNU), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)
Subjects: Physics, methods: statistical, Solar System, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], business.industry, Group (mathematics), [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astronomy and Astrophysics, Centaur, Astrophysics, 01 natural sciences, Red Color, Interpretation (model theory), Set (abstract data type), techniques: photometric, Optics, Space and Planetary Science, Taxonomy (general), 0103 physical sciences, Kuiper Belt, Trans-Neptunian object, business, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: The original publication is available at http://iopscience.iop.org/1538-3881/.; International audience; Trans-Neptunian objects (TNOs) and Centaurs display thewidest color diversity in comparison to other small solar system bodies. The investigation of their properties can help in understanding the evolution of these objects. In this paper we propose a classification scheme based on multivariate statistical analysis of a homogeneous, high-quality set of B - V, V - R, V - I , and V - J color indices. Analyzing a sample of 51 objects and using a high confidence level, four groups have been identified and named: BB, BR, IR, and RR. The group BB contains objects with neutral color and RR those with very red color, while the others have intermediate behavior. We extend the analysis to 84 other objects for which three colors are available, obtaining a preliminary classification. A tentative interpretation of these groups in terms of surface characteristics is given.
Published: 2005

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