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1. Targeting of 3D oral cancer spheroids by αVβ6 integrin using near-infrared peptide-conjugated IRDye 680

Author: L. Dirheimer, T. Pons, A. François, L. Lamy, S. Cortese, F. Marchal, and L. Bezdetnaya
Subjects: Head and neck cancer, Oral cancer, Tongue cancer, αVβ6 integrin, Spheroid, Fluorescence imaging, Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282, Cytology, QH573-671
Abstract: Abstract Background In the treatment of oral cavity cancer, margin status is one of the most critical prognostic factors. Positive margins are associated with higher local recurrence and lower survival rates. Therefore, the universal goal of oral surgical oncology is to achieve microscopically clear margins. Near-infrared fluorescence guided surgery (FGS) could improve surgical resection using fluorescent probes. αVβ6 integrin has shown great potential for cancer targeting due to its overexpression in oral cancers. Red fluorescent contrast agent IRDye 680 coupled with anti-αVβ6 peptide (IRDye-A20) represents an asset to improve FGS of oral cancer. This study investigates the potential of IRDye-A20 as a selective imaging agent in 3D three-dimensional tongue cancer cells. Methods αVβ6 integrin expression was evaluated by RT-qPCR and Western Blotting in 2D HSC-3 human tongue cancer cells and MRC-5 human fibroblasts. Targeting ability of IRDye-A20 was studied in both cell lines by flow cytometry technique. 3D tumor spheroid models, homotypic (HSC-3) and stroma-enriched heterotypic (HSC-3/MRC-5) spheroids were produced by liquid overlay procedure and further characterized using (immuno)histological and fluorescence-based techniques. IRDye-A20 selectivity was evaluated in each type of spheroids and each cell population. Results αVβ6 integrin was overexpressed in 2D HSC-3 cancer cells but not in MRC-5 fibroblasts and consistently, only HSC-3 were labelled with IRDye-A20. Round shaped spheroids with an average diameter of 400 μm were produced with a final ratio of 55%/45% between HSC-3 and MRC-5 cells, respectively. Immunofluorescence experiments demonstrated an uniform expression of αVβ6 integrin in homotypic spheroid, while its expression was restricted to cancer cells only in heterotypic spheroid. In stroma-enriched 3D model, Cytokeratin 19 and E-cadherin were expressed only by cancer cells while vimentin and fibronectin were expressed by fibroblasts. Using flow cytometry, we demonstrated that IRDye-A20 labeled the whole homotypic spheroid, while in the heterotypic model all cancer cells were highly fluorescent, with a negligible fluorescence in fibroblasts. Conclusions The present study demonstrated an efficient selective targeting of A20FMDV2-conjugated IRDye 680 in 3D tongue cancer cells stroma-enriched spheroids. Thus, IRDye-A20 could be a promising candidate for the future development of the fluorescence-guided surgery of oral cancers. Graphical Abstract
Published: 2024
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2. Quantification of magnetosphere–ionosphere coupling timescales using mutual information: response of terrestrial radio emissions and ionospheric–magnetospheric currents

Author: A. R. Fogg, C. M. Jackman, S. C. Chapman, J. E. Waters, A. Bergin, L. Lamy, K. Issautier, B. Cecconi, and X. Bonnin
Subjects: Science, Physics, QC1-999, Geophysics. Cosmic physics, QC801-809
Abstract: Auroral kilometric radiation (AKR) is a terrestrial radio emission excited by the same accelerated electrons which excite auroral emissions. Although it is well correlated with auroral and geomagnetic activity, the coupling timescales between AKR and different magnetospheric or ionospheric regions have yet to be determined. Estimation of these coupling timescales is non-trivial as a result of complex, non-linear processes which rarely occur in isolation. In this study, the mutual information between AKR intensity and different geomagnetic indices is used to assess the correlation between variables. Indices are shifted to different temporal lags relative to AKR intensity, and the lag at which the variables have the most shared information is found. This lag is interpreted as the coupling timescale. The AKR source region receives the effects of a shared driver before the auroral ionosphere. Conversely, the polar ionosphere reacts to a shared driver before the AKR source region. Bow shock interplanetary magnetic field BZ is excited about 1 h before AKR enhancements. This work provides quantitatively determined temporal context to the coupling timelines at Earth. The results suggest that there is a sequence of excitation following the onset of a shared driver: first, the polar ionosphere feels the effects, followed by the AKR source region and then the auroral ionosphere.
Published: 2024
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3. Jupiter radio emission probability tool

Author: B. Cecconi, S. Aicardi, and L. Lamy
Subjects: jupiter, radio emissions, space physics, online application, observation planning, python, Astronomy, QB1-991, Geophysics. Cosmic physics, QC801-809
Abstract: Jupiter is a source of intense radio emissions in the decametric wavelength range observable from ground (above ∼10 MHz) and from space (down to a few kHz). The strong anisotropy of the Jovian radio sources results in characteristic shapes in the temporal-spectral domain, which can be used to identified the various types of Jovian radio components. The Jupiter Probability Tool provides users with Jovian radio emission observability predictions, depending on the observers location, and the radio emission class. The application can be used for observation planning or data analysis for ground or space observations.
Published: 2023
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4. Relationship between solar wind corotating interaction regions and the phasing and intensity of Saturn kilometric radiation bursts

Author: S. V. Badman, S. W. H. Cowley, L. Lamy, B. Cecconi, and P. Zarka
Subjects: Science, Physics, QC1-999, Geophysics. Cosmic physics, QC801-809
Abstract: Voyager spacecraft measurements of Saturn kilometric radiation (SKR) identified two features of these radio emissions: that they pulse at a period close to the planetary rotation period, and that the emitted intensity is correlated with the solar wind dynamic pressure (Desch and Kaiser, 1981; Desch, 1982; Desch and Rucker, 1983). In this study the inter-relation between the intensity and the pulsing of the SKR is analysed using Cassini spacecraft measurements of the interplanetary medium and SKR over the interval encompassing Cassini's approach to Saturn, and the first extended orbit. Cassini Plasma Spectrometer ion data were only available for a subset of the dates of interest, so the interplanetary conditions were studied primarily using the near-continuously available magnetic field data, augmented by the ion moment data when available. Intense SKR bursts were identified when solar wind compressions arrived at Saturn. The intensity of subsequent emissions detected by Cassini during the compression intervals was variable, sometimes remaining intense for several planetary rotations, sometimes dimming and rarely disappearing. The timings of the initial intense SKR peaks were sometimes independent of the long-term pulsing behaviour identified in the SKR data. Overall, however, the pulsing of the SKR peaks during the disturbed intervals was not significantly altered relative to that during non-compression intervals.
Published: 2008
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5. Magnetosphere‐Ionosphere‐Thermosphere Coupling Study at Jupiter Based on Juno's First 30 Orbits and Modeling Tools

Author: S. Al Saati, N. Clément, C. Louis, M. Blanc, Y. Wang, N. André, L. Lamy, B. Bonfond, B. Collet, F. Allegrini, S. Bolton, G. Clark, J. E. P. Connerney, J.‐C. Gérard, G. R. Gladstone, S. Kotsiaros, W. S. Kurth, and B. Mauk
Published: 2022
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6. Solar Wind Dynamic Pressure Upstream From Saturn: Estimation From Magnetosheath Properties and Comparison With SKR

Author: M. F. Thomsen, C. M. Jackman, and L. Lamy
Published: 2019
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7. Saturn's Northern Aurorae at Solstice From HST Observations Coordinated With Cassini's Grand Finale

Author: L. Lamy, R. Prangé, C. Tao, T. Kim, S. V. Badman, P. Zarka, B. Cecconi, W. S. Kurth, W. Pryor, E. Bunce, and A. Radioti
Published: 2018
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8. Near-Sun Observations of an F-Corona Decrease and K-Corona Fine Structures

Author: R A Howard, A Vourlidas, V Bothmer, R C Colaninno, C E DeForest, B Gallagher, J R Hall, P Hess, A K Higginson, C M Korendyke, A Kouloumvakos, P L Lamy, P C Liewer, J Linker, M Linton, P Penteado, S P Plunkett, N Poirier, N E Raouafi, N Rich, P Rochus, A P Rouillard, D G Socker, G Stenborg, A F Thernisien, and N M Viall
Subjects: Solar Physics
Abstract: Remote observations of the solar photospheric light scattered by electrons (K-corona) and dust (F-corona/Zodiacal light) have been made from the ground during eclipses and from space at 1 AU and as close as 0.3 AU. Previous observations of dust scattering have not confirmed the existence of a theoretically-predicted dust free zone near the Sun. The transient nature of the corona has been well characterized for large events, but questions still remain (e.g. initiation, production of solar energetic particles) and for small events even the structure is uncertain. Here we report on imaging the solar corona, from the Parker Solar Probe spacecraft, during the first two perihelion passes (0.16-0.25 AU), each of ten days duration. The view from these distances is qualitatively similar to the historical view, but there are some significant differences in the details. We have uncovered at short elongations a decrease in the intensity of the F-coronal intensity, which is suggestive of the long-sought dust free zone. Also we have resolved the plasma structure of very small eruptions, which are being frequently ejected from the Sun. They take two forms - the commonly observed magnetic flux ropes or the predicted, but not yet observed, magnetic islands arising from the tearing mode instability in the current sheet. Our observations of the coronal streamer evolution confirm the large-scale topology of the solar corona, but they also reveal that, as recently predicted, streamers are composed of yet smaller sub-streamers channeling continual density fluctuations at all visible scales.
Published: 2019
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9. Auroral Storm and Polar Arcs at Saturn—Final Cassini/UVIS Auroral Observations

Author: B. Palmaerts, A. Radioti, D. Grodent, Z. H. Yao, T. J. Bradley, E. Roussos, L. Lamy, E. J. Bunce, S. W. H. Cowley, N. Krupp, W. S. Kurth, J.‐C. Gérard, and W. R. Pryor
Published: 2018
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10. Multi‐instrument Investigation of the Location of Saturn's Magnetotail X‐Line

Author: A. W. Smith, C. M. Jackman, M. F. Thomsen, L. Lamy, and N. Sergis
Published: 2018
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11. Low‐Frequency Extensions of the Saturn Kilometric Radiation as a Proxy for Magnetospheric Dynamics

Author: J. J. Reed, C. M. Jackman, L. Lamy, W. S. Kurth, and D. K. Whiter
Published: 2018
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12. Io‐Jupiter decametric arcs observed by Juno/Waves compared to ExPRES simulations

Author: C. K. Louis, L. Lamy, P. Zarka, B. Cecconi, M. Imai, W. S. Kurth, G. Hospodarsky, S. L. G. Hess, X. Bonnin, S. Bolton, J. E. P. Connerney, and S. M. Levin
Published: 2017
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13. The aurorae of Uranus past equinox

Author: L. Lamy, R. Prangé, K. C. Hansen, C. Tao, S. W. H. Cowley, T. S. Stallard, H. Melin, N. Achilleos, P. Guio, S. V. Badman, T. Kim, and N. Pogorelov
Published: 2017
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14. Wind/WAVES Observations of Auroral Kilometric Radiation: Automated Burst Detection and Terrestrial Solar Wind ‐ Magnetosphere Coupling Effects

Author: A. R. Fogg, C. M. Jackman, J. E. Waters, X. Bonnin, L. Lamy, B. Cecconi, K. Issautier, C. K. Louis, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), 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 Paris Cité (UPCité), 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: Geophysics, auroral kilometric radiation, solar wind, [SDU]Sciences of the Universe [physics], Space and Planetary Science, Astrophysics::High Energy Astrophysical Phenomena, Physics::Space Physics, magnetosphere, geomagnetic activity, automated event selection, terrestrial radio emission
Abstract: International audience; Auroral Kilometric Radiation (AKR) is the strongest terrestrial radio emission, and emanates from the same electron acceleration regions from which particles precipitate into the ionosphere, exciting the aurorae and other phenomena. As such, AKR is a barometer for the state of solar wind - magnetosphere - ionosphere coupling. AKR is anisotropically beamed in a hollow cone from a source region generally found at nightside local times, meaning that a single source region cannot be viewed from all local times in the magnetosphere. In radio data such as dynamic spectra, AKR is frequently observed simultaneously to other radio emissions which can have a similar intensity and frequency range, making it difficult to automatically detect. Building on a previously published pipeline to extract AKR emissions from Wind/WAVES data, in this paper a novel automated AKR burst detection technique is presented and applied to Wind/WAVES data. Over a five year interval, about 5000 AKR bursts are detected with median burst length ranging from about 30 to 60 min. During detected burst windows, higher solar wind velocity is observed, and the interplanetary magnetic field clock angle is observed to tend toward BZ < 0, BY < 0, when compared with the entire statistical interval. Additionally, higher geomagnetic activity is observed during burst windows at polar, high and equatorial latitudes.
Published: 2022
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15. A Comprehensive Set of Juno In Situ and Remote Sensing Observations of the Ganymede Auroral Footprint

Author: V. Hue, J. R. Szalay, T. K. Greathouse, B. Bonfond, S. Kotsiaros, C. K. Louis, A. H. Sulaiman, G. Clark, F. Allegrini, G. R. Gladstone, C. Paranicas, M. H. Versteeg, A. Mura, A. Moirano, D. J. Gershman, S. J. Bolton, J. E. P. Connerney, M. W. Davis, R. W. Ebert, J.‐C. Gérard, R. S. Giles, D. C. Grodent, M. Imai, J. A. Kammer, W. S. Kurth, L. Lamy, B. H. Mauk, Southwest Research Institute [San Antonio] (SwRI), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), 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 Paris Cité (UPCité), 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), Johns Hopkins University (JHU), and This work is dedicated to Franck Hersant, whose generosity, talent and humbleness was an inspirational force. We are grateful to NASA and contributing institutions that have made the Juno mission possible. This work was funded by the NASA New Frontiers Program for Juno (managed by the Jet Propulsion Laboratory) via a subcontract with Southwest Research Institute. This research was supported through Contract 699041X at the University of Iowa, and through Contract NNM06AA75 C with the Southwest Research Institute at Princeton University. BB, JCG, and DG acknowledge funding for this research by a PRODEX contract of ESA, managed with the help of BELSPO. CL's work at DIAS is supported by the Science Foundation Ireland Grant 18/FRL/6199. LL and CL acknowledge the support from CNES and CNRS/INSU programs of planetology and heliophysics. The work of MI was supported by the JSPS KAKENHI Grant Number JP20K22371.
Subjects: Jupiter Ganymede Juno, Geophysics, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Astrophysics::High Energy Astrophysical Phenomena, Physics::Space Physics, General Earth and Planetary Sciences, Astrophysics::Earth and Planetary Astrophysics
Abstract: International audience; Jupiter's satellite auroral footprints are a manifestation of the satellite-magnetosphere interaction of the Galilean moons. Juno's polar elliptical orbit enables crossing the magnetic flux tubes connecting each Galilean moon with their associated auroral emission. Its payload allows measuring the fields and particle population in the flux tubes while remotely sensing their associated auroral emissions. During its thirtieth perijove, Juno crossed the flux tube directly connected to Ganymede's leading footprint spot, a unique event in the entire Juno prime mission. Juno revealed a highly-structured precipitating electron flux, up to 316 mW/m2, while measuring both a small perturbation in the magnetic field azimuthal component and small Poynting flux with an estimated total downward current of 4.2 ± 1.2 kA. Based on the evolution of the footprint morphology and the field and particle measurements, Juno transited for the first time through a region connected to the transhemispheric electron beam of the Ganymede footprint.
Published: 2022
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16. Empirical selection of Auroral Kilometric Radiation during a multipoint remote observation with Wind and Cassini

Author: J. E. Waters, X. Bonnin, Daniel Whiter, L. Lamy, Baptiste Cecconi, A. R. Fogg, C. M. Jackman, K. Issautier, 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), Observatoire de Paris, and Université Paris sciences et lettres (PSL)
Subjects: 010504 meteorology & atmospheric sciences, Auroral kilometric radiation, 01 natural sciences, Remote observation, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Geophysics, 13. Climate action, Space and Planetary Science, 0103 physical sciences, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Geology, Selection (genetic algorithm), ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Remote sensing
Abstract: Auroral Kilometric Radiation (AKR) is terrestrial radio emission that originates in particle acceleration regions along magnetic field lines, coinciding with discrete auroral arcs. AKR viewing geometry is complex due to the confinement of the source regions to nightside local times (LTs) and the anisotropy of the beaming pattern, so observations are highly dependent on spacecraft viewing position. We present a novel, empirical technique that selects AKR emission from observations made with the spin-axis aligned antenna of the Wind/WAVES instrument, based on the rapidly varying amplitude of AKR across spacecraft spin timescales. We apply the technique to Wind/WAVES data during 1999 day of year 227–257, when the Cassini spacecraft flew past Earth and provided an opportunity to observe AKR from two remote locations. We examine the AKR flux and power, with observations made from LTs of 1700–0300 hr having an average power up to 10 4 Wsr -1 larger than those on the dayside and an increasing AKR power observed at higher magnetic latitudes. We perform a linear cross-correlation between the Wind AKR power and the spacecraft magnetic latitude, showing positive then negative correlation as Wind travels from the Northern to Southern magnetic hemisphere. Statistically significant diurnal modulations are found in the whole 30-day period and in subsets of the data covering different local time sectors, indicative of a predominantly geometrical effect for remote AKR viewing. The reproduction of well-known features of the AKR verifies the empirical selection and shows the promise of its application to Wind/WAVES observations.
Published: 2021
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17. Jupiter’s auroral radio emissions observed by Cassini: rotational versus solar wind control, and components identification

Author: M. S. Marques, Renée Prangé, Corentin Louis, Baptiste Cecconi, Ezequiel Echer, Philippe Zarka, L. Lamy, Fabíola Pinho Magalhães, 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), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Universidade Federal do Rio Grande do Norte [Natal] (UFRN), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-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)-Centre National de la Recherche Scientifique (CNRS), Dublin Institute for Advanced Studies (DIAS), Instituto Nacional de Pesquisas Espaciais (INPE), Ministério da Ciência, Tecnologia e Inovação, Programme National de Planetologie and the Programme National Soleil-Terre of CNRS-INSU, ANR-11-LABX-0062,PLAS@PAR,PLASMAS à PARIS, au delà des frontières(2011), 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), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), 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), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and 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)
Subjects: Physics, 010504 meteorology & atmospheric sciences, Magnetosphere, Astrophysics, 01 natural sciences, Jovian, Jupiter, Solar wind, Geophysics, Amplitude, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Local time, 0103 physical sciences, Decametre, Longitude, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: International audience; Reanalyzing Cassini radio observations performed during Jupiter’s flyby of 2000-2001, we study the internal (rotational) versus external (solar wind) control of Jupiter’s radio emissions, from kilometer to decameter wavelengths, and the relations between the different auroral radio components. For that purpose, we build a database of the occurrence of Jovian auroral radio components bKOM, HOM and DAM observed by Cassini, and then frequency-longitude stacked plots of the polarized intensity of these radio components. Comparing the results obtained inbound and outbound, as a function of the Observer’s or Sun’s longitude, we find that HOM & DAM are dominantly rotation-modulated (i.e. emitted from searchlight-like sources fixed in Jovian longitude), whereas bKOM is modulated more strongly by the solar wind than by the rotation (i.e. emitted from sources more active within a given Local Time sector). We propose a simple analytical description of these internal and external modulations and evaluate its main parameters (the amplitude of each control) for HOM+DAM and bKOM. Comparing Cassini and Nançay Decameter Array data, we find that HOM is primarily connected to the decameter emissions originating from the dusk sector of the Jovian magnetosphere. HOM and DAM components form a complex but stable pattern in the frequency-longitude plane. HOM also seems to be related to the ‘lesser arcs’ identified by Voyager. bKOM consists of a main part above urn:x-wiley:21699380:media:jgra56786:jgra56786-math-000140 kHz in antiphase with HOM occurrence, and detached patches below urn:x-wiley:21699380:media:jgra56786:jgra56786-math-000280 kHz in phase with HOM. The frequency-longitude patterns formed by DAM, HOM and bKOM remain to be modelled.
Published: 2021
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18. Low-frequency monitoring of flare star binary CR Draconis::Long-term electron-cyclotron maser emission

Author: Joseph R. Callingham, K. C. Veken, Harish Vedantham, J. Sabater, H. J. A. Röttgering, Timothy W. Shimwell, Cyril Tasse, S. E. B. Toet, Adina D. Feinstein, R. J. van Weeren, Philippe Zarka, T. P. Ray, Benjamin J. S. Pope, L. Lamy, Philip Best, 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), and Astronomy
Subjects: Rotation period, Stars, Stars: Individual, Solar System, astro-ph.SR, 010504 meteorology & atmospheric sciences, Radio Continuum, Gas giant, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Spectral line, law.invention, Jupiter, CR Draconis Astrophysics, law, stars: low-mass, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Solar and Stellar Astrophysics, Maser, Low-Mass, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Flare star, Astronomy and Astrophysics, Stars, 3. Good health, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Stars: Individual, Brightness temperature, astro-ph.EP, stars: individual: CR Draconis, Earth and Planetary Astrophysics, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], radio continuum: stars, Astrophysics - Earth and Planetary Astrophysics
Abstract: Recently detected coherent low-frequency radio emission from M dwarf systems shares phenomenological similarities with emission produced by magnetospheric processes from the gas giant planets of our Solar System. Such beamed electron-cyclotron maser emission can be driven by a star-planet interaction or a breakdown in co-rotation between a rotating plasma disk and a stellar magnetosphere. Both models suggest that the radio emission could be periodic. Here we present the longest low-frequency interferometric monitoring campaign of an M dwarf system, composed of twenty-one $\approx$8 hour epochs taken in two series of observing blocks separated by a year. We achieved a total on-source time of 6.5 days. We show that the M dwarf binary CR Draconis has a low-frequency 3$\sigma$ detection rate of 90$^{+5}_{-8}$% when a noise floor of $\approx$0.1 mJy is reached, with a median flux density of 0.92 mJy, consistent circularly polarised handedness, and a median circularly polarised fraction of 66%. We resolve three bright radio bursts in dynamic spectra, revealing the brightest is elliptically polarised, confined to 4 MHz of bandwidth centred on 170 MHz, and reaches a flux density of 205 mJy. The burst structure is mottled, indicating it consists of unresolved sub-bursts. Such a structure shares a striking resemblance with the low-frequency emission from Jupiter. We suggest the near-constant detection of high brightness temperature, highly-circularly-polarised radiation that has a consistent circular polarisation handedness implies the emission is produced via the electron-cyclotron maser instability. Optical photometric data reveal the system has a rotation period of 1.984$\pm$0.003 days. We observe no periodicity in the radio data, but the sampling of our radio observations produces a window function that would hide the near two-day signal., Comment: Accepted for publication in A&A, 16 pages, 7 figures, 2 tables
Published: 2021
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19. Magnetospheric Studies: A requirement for addressing interdisciplinary mysteries in the Ice Giant systems

Author: Peter Kollmann, F. Allegini, R. C. Allen, N. André, A. R. Azari, F. Bagenal, C. B. Beddingfield, D. Brain, P. Brandt, X. Cao, R. J. Cartwright, G. Clark, I. Cohen, J. F. Cooper, F. Crary, E. J. Leonard, C. Paty, I. de Pater, R. T. Desai, G. A. DiBraccio, W. Dietrich, C. Dong, R. W. Ebert, M. Felici, R. J. Filwett, G. Fischer, D. J. Gershman, M. Gkioulidou, T. K. Greathouse, L. Griton, M. Gritsevich, K. Hibbitts, G. Hospodarsky, V. Hue, G. Hunt, H. L. F. Huybrighs, M. Imai, C. M. Jackman, J. M. Jasinski, X. Jia, I. Jun, A. Kotova, W. S. Kurth, L. Lamy, J. Lazio, S. Lejosne, C. Louis, A. Masters, B. Mauk, H. Madanian, K. E. Mandt, R. McNutt, Jr., H. Melin, S. Miller, L. Moore, Q. Nenon, F. M. Neubauer, T. Nordheim, B. Palmaerts, C. Paranicas, P. Phipps, L. Regoli, K. Retherford, L. Roth, E. Roussos, K. D. Runyon, A. Rymer, J. Saur, D. Santos-Costa, Y. Y. Shprits, L. J. Spilker, T. Stallard, A. G. Smirnov, K. Soderlund, S. Stanley, A. H. Sulaiman, J. R. Szalay, D. L. Turner, S. Vines, L. Wang, B. Weiss, J. Wicht, R. J. Wilson, and E. Woodfield
Subjects: 010504 meteorology & atmospheric sciences, 0103 physical sciences, 010303 astronomy & astrophysics, 01 natural sciences, Geology, Ice giant, 0105 earth and related environmental sciences, Astrobiology
Published: 2021
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20. First observations and performance of the RPW instrument on board the Solar Orbiter mission

Author: M. Maksimovic, J. Souček, T. Chust, Y. Khotyaintsev, M. Kretzschmar, X. Bonnin, A. Vecchio, O. Alexandrova, S. D. Bale, D. Bérard, J.-Y. Brochot, N. J. T. Edberg, A. Eriksson, L. Z. Hadid, E. P. G. Johansson, T. Karlsson, B. Katra, V. Krasnoselskikh, V. Krupař, S. Lion, E. Lorfèvre, L. Matteini, Q. N. Nguyen, D. Píša, R. Piberne, D. Plettemeier, H. O. Rucker, O. Santolík, K. Steinvall, M. Steller, Š. Štverák, P. Trávníček, A. Vaivads, A. Zaslavsky, S. Chaintreuil, M. Dekkali, P.-A. Astier, G. Barbary, K. Boughedada, B. Cecconi, F. Chapron, C. Collin, D. Dias, L. Guéguen, L. Lamy, V. Leray, L. R. Malac-Allain, F. Pantellini, J. Parisot, P. Plasson, S. Thijs, I. Fratter, E. Bellouard, P. Danto, S. Julien, E. Guilhem, C. Fiachetti, J. Sanisidro, C. Laffaye, F. Gonzalez, B. Pontet, N. Quéruel, G. Jannet, P. Fergeau, T. Dudok de Wit, T. Vincent, C. Agrapart, J. Pragout, M. Bergerard-Timofeeva, G. T. Delory, P. Turin, A. Jeandet, P. Leroy, J.-C. Pellion, V. Bouzid, W. Recart, I. Kolmašová, O. Krupařová, L. Uhlíř, R. Lán, J. Baše, M. André, L. Bylander, V. Cripps, C. Cully, S.-E. Jansson, W. Puccio, J. Břínek, H. Ottacher, V. Angelini, M. Berthomier, V. Evans, K. Goetz, P. Hellinger, T. S. Horbury, K. Issautier, E. Kontar, O. Le Contel, P. Louarn, M. Martinović, D. Müller, H. O’Brien, C. J. Owen, A. Retino, J. Rodríguez-Pacheco, F. Sahraoui, L. Sanchez, A. P. Walsh, R. F. Wimmer-Schweingruber, I. Zouganelis, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), 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 Paris Cité (UPCité), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Swedish Institute of Space Physics [Uppsala] (IRF), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-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 d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Centre National d'Études Spatiales [Toulouse] (CNES), Innovations for High Performance Microelectronics (IHP), Institut für Weltraumforschung = Space Research institute [Graz] (IWF), Osterreichische Akademie der Wissenschaften (ÖAW), Centre Hospitalier Régional Universitaire de Tours (CHRU Tours), Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), Centre Hospitalier Lyon Sud [CHU - HCL] (CHLS), Hospices Civils de Lyon (HCL), ALTRAN (FRANCE), GeNeuro Innovation [Lyon], Hôpital Saint Eloi (CHRU Montpellier), Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier), Institut des Neurosciences de Montpellier (INM), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM), Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR), Nexeya Conseil & Formation, Institute of Atmospheric Physics [Prague] (IAP), Czech Academy of Sciences [Prague] (CAS), Microbes, Intestin, Inflammation et Susceptibilité de l'Hôte (M2iSH), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre de Recherche en Nutrition Humaine d'Auvergne (CRNH d'Auvergne)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Clermont Auvergne (UCA), Service de Médecine Interne [CHU Clermont-Ferrand], CHU Gabriel Montpied [Clermont-Ferrand], CHU Clermont-Ferrand-CHU Clermont-Ferrand, Royal Institute of Technology [Stockholm] (KTH ), Department of Physics and Astronomy [Calgary], University of Calgary, Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), NOAA National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), National Institute of Water and Atmospheric Research [Wellington] (NIWA), Department of Physics [Imperial College London], Imperial College London, Université Paris sciences et lettres (PSL), Institut de recherche en astrophysique et planétologie (IRAP), 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), 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)-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), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, University of Belgrade [Belgrade], Laboratoire des sciences de l'ingénieur, de l'informatique et de l'imagerie (ICube), École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Université de Strasbourg (UNISTRA)-Institut National des Sciences Appliquées - Strasbourg (INSA Strasbourg), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de Recherche en Informatique et en Automatique (Inria)-Les Hôpitaux Universitaires de Strasbourg (HUS)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU), International Centre for Radio Astronomy Research - Curtin University, Curtin University [Perth], Planning and Transport Research Centre (PATREC)-Planning and Transport Research Centre (PATREC), European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), 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), University of California [Berkeley], University of California-University of California, Institut für Weltraumforschung [Graz] (IWF), CHU Saint-Eloi, Institut des Neurosciences de Montpellier - Déficits sensoriels et moteurs (INM), Université de Montpellier (UM)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut national des sciences de l'Univers (INSU - CNRS)-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)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées - Strasbourg (INSA Strasbourg), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-École Nationale du Génie de l'Eau et de l'Environnement de Strasbourg (ENGEES)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), European Space Agency (ESA), and Centre Hospitalier Régional Universitaire de Tours (CHRU TOURS)
Subjects: Sun: general, 010504 meteorology & atmospheric sciences, Astronomy, Astrophysics, 01 natural sciences, 7. Clean energy, law.invention, Orbiter, Astronomi, astrofysik och kosmologi, law, 0103 physical sciences, Astronomy, Astrophysics and Cosmology, Aerospace engineering, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Sun: radio radiation, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, Sun, Astronomy and Astrophysics, solar wind, Space and Planetary Science, general, radio radiation, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: International audience; The Radio and Plasma Waves (RPW) instrument on the ESA Solar Orbiter mission is designed to measure in situ magnetic and electric fields and waves from the continuum up to several hundred kHz. The RPW also observes solar and heliospheric radio emissions up to 16 MHz. It was switched on and its antennae were successfully deployed two days after the launch of Solar Orbiter on February 10, 2020. Since then, the instrument has acquired enough data to make it possible to assess its performance and the electromagnetic disturbances it experiences. In this article, we assess its scientific performance and present the first RPW observations. In particular, we focus on a statistical analysis of the first observations of interplanetary dust by the instrument’s Thermal Noise Receiver. We also review the electro-magnetic disturbances that RPW suffers, especially those which potential users of the instrument data should be aware of before starting their research work.
Published: 2021
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21. Science Goals and Mission Objectives for the Future Exploration of Ice Giants Systems: A Horizon 2061 Perspective

Author: J. Schmidt, Olivier Mousis, Sébastien Charnoz, Ravit Helled, Krista M. Soderlund, Olivier Witasse, Pierre Vernazza, Elizabeth P. Turtle, Nicolas André, Jonathan I. Lunine, Alexis Bouquet, L. Lamy, Corentin Louis, Magali Deleuil, Kathleen L. Craft, Kathleen Mandt, Léa Griton, Ricardo Hueso, Thomas Ronnet, Michel Blanc, Diego Turrini, University of Zurich, Blanc, Michel, 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), 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: Solar System, 010504 meteorology & atmospheric sciences, 530 Physics, Computer science, 7. Clean energy, 01 natural sciences, Space exploration, Astrobiology, law.invention, Jupiter, Orbiter, 1912 Space and Planetary Science, Planet, Neptune, law, 0103 physical sciences, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Uranus, Astronomy and Astrophysics, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, 10231 Institute for Computational Science, 3103 Astronomy and Astrophysics, Ice giant
Abstract: The comparative study of planetary systems is a unique source of new scientific insight: following the six “key science questions” of the “Planetary Exploration, Horizon 2061” long-term foresight exercise, it can reveal to us the diversity of their objects (Question 1) and of their architectures (Question 2), help us better understand their origins (Question 3) and how they work (Question 4), find and characterize habitable worlds (Question 5), and ultimately, search for alien life (Question 6). But a huge “knowledge gap” exists which limits the applicability of this approach in the solar system itself: two of its secondary planetary systems, the ice giant systems of Uranus and Neptune, remain poorly explored. Starting from an analysis of our current limited knowledge of solar system ice giants and their systems in the light of these six key science questions, we show that a long-term plan for the space exploration of ice giants and their systems will greatly contribute to answer these questions. To do so, we identify the key measurements needed to address each of these questions, the destinations to choose (Uranus, Neptune, Triton or a subset of them), the combinations of space platform(s) and the types of flight sequences needed. We then examine the different launch windows available until 2061, using a Jupiter fly-by, to send a mission to Uranus or Neptune, and find that: (1) an optimized choice of platforms and flight sequences makes it possible to address a broad range of the key science questions with one mission at one of the planets. Combining an atmospheric entry probe with an orbiter tour starting on a high-inclination, low periapse orbit, followed by a sequence of lower inclination orbits (or the other way around) appears to be an optimal choice. (2) a combination of two missions to each of the ice giant systems, to be flown in parallel or in sequence, will address five out of the six key questions and establish the prerequisites to address the sixth one: searching for life at one of the most promising Ice Giant moons. (3) The 2032 Jupiter fly-by window, which offers a unique opportunity to implement this plan, should be considered in priority; if this window cannot be met, using the 2036 Jupiter fly-by window to send a mission to Uranus first, and then the 2045 window for a mission to Neptune, will allow one to achieve the same objectives; as a back-up option, one should consider an orbiter + probe mission to one of the planets and a close fly-by of the other planet to deliver a probe into its atmosphere, using the opportunity of a future mission on its way to Kuiper Belt Objects or the interstellar medium; (4) based on the examination of the habitability of the different moons by the first two missions, a third one can be properly designed to search for life at the most promising moon, likely Triton, or one of the active moons of Uranus. Thus, by 2061 the first two missions of this plan can be implemented and a third mission focusing on the search for life can be designed. Given that such a plan may be out of reach of a single national agency, international collaboration is the most promising way to implement it.
Published: 2020
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22. Direct radio discovery of a cold brown dwarf

Author: Zhoujian Zhang, Philippe Zarka, Joseph R. Callingham, L. Lamy, Aleksandar Shulevski, Timothy W. Shimwell, H. J. A. Röttgering, William M. J. Best, Kaushik De, Harish Vedantham, Michael C. Liu, Trent J. Dupuy, Astronomy, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), 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)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
Subjects: ELECTRON-CYCLOTRON MASER, astro-ph.SR, 010504 meteorology & atmospheric sciences, IMAGER, Astrophysics::High Energy Astrophysical Phenomena, Population, Brown dwarf, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Stellar classification, 01 natural sciences, T-DWARFS, law.invention, Luminosity, law, SEARCH, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Maser, education, Spectroscopy, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, SPECTRAL CLASSIFICATION, 0105 earth and related environmental sciences, Physics, [PHYS]Physics [physics], Earth and Planetary Astrophysics (astro-ph.EP), education.field_of_study, CONSTRAINTS, Astronomy and Astrophysics, LOFAR, Photometry (astronomy), DEFINITION, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, ALL-SKY SURVEY, astro-ph.EP, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], EMISSION, Astrophysics - Earth and Planetary Astrophysics, PLANETS
Abstract: Magnetospheric processes seen in gas-giants such as aurorae and circularly-polarized cyclotron maser radio emission have been detected from some brown dwarfs. However, previous radio observations targeted known brown dwarfs discovered via their infrared emission. Here we report the discovery of BDR J1750+3809, a circularly polarized radio source detected around 144 MHz with the LOFAR telescope. Follow-up near-infrared photometry and spectroscopy show that BDR J1750+3809 is a cold methane dwarf of spectral type T$6.5\pm 1$ at a distance of $65^{+9}_{-8}\,{\rm pc}$. The quasi-quiescent radio spectral luminosity of BDR J1750+3809 is $\approx 5\times 10^{15}\,{\rm erg}\,{\rm s}^{-1}\,{\rm Hz}^{-1}$ which is over two orders of magnitude larger than that of the known population of comparable spectral type. This could be due to a preferential geometric alignment or an electrodynamic interaction with a close companion. In addition, as the emission is expected to occur close to the electron gyro-frequency, the magnetic field strength at the emitter site in BDR J1750+3809 is $B\gtrsim 25\,{\rm G}$, which is comparable to planetary-scale magnetic fields. Our discovery suggests that low-frequency radio surveys can be employed to discover sub-stellar objects that are too cold to be detected in infrared surveys., Comment: Accepted for publication in ApJL
Published: 2020
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23. Volume uncertainty of (7) Iris shape models from disc-resolved images

Author: Laurent Jorda, P. Michel, Miroslav Brož, Michael Marsset, P. Bartczak, H. Le Coroller, Jérôme Berthier, Matti Viikinkoski, Paolo Tanga, Marin Ferrais, Benoit Carry, Arthur Vigan, Bin Yang, Pierre Vernazza, P. L. Lamy, Christophe Dumas, Tadeusz Michalowski, Toni Santana-Ros, Alexis Drouard, Romain Fétick, Grzegorz Dudziński, Julie Castillo-Rogez, M. Birlan, F. Vachier, S. Benseguane, Thierry Fusco, Agnieszka Kryszczyńska, E. Podlewska-Gaca, Fabrice Cipriani, Olivier Witasse, F. Marchis, Josef Hanus, Nicolas Rambaux, Emmanuel Jehin, A. Marciniak, François Colas, Universidad de Alicante. Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Adam Mickiewicz University in Poznań (UAM), Astronomical Observatory [Poznan], Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-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), Charles University [Prague] (CU), Institute of Astronomy [Prague], 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), Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA), SETI Institute, Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), University of Tampere [Finland], Astronomical Institute of Romanian Academy, Romanian Academy, Space Sciences, Technologies and Astrophysics Research Institute (STAR), Université de Liège, 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, 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), 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), Departamento de Fisica, Ingenieria de Sistemas y Teoria de la Señal [Alicante] (DFESTS), Universidad de Alicante, Institut de Ciencies del Cosmos (ICCUB), Universitat de Barcelona (UB), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), European Project: 871149,EPN2024-RI, Czech Science Foundation, European Commission, Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), 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 Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS, Laboratoire Lagrange, Nice, France
Subjects: asteroids, Surface (mathematics), Solar System, 010504 meteorology & atmospheric sciences, photometric -minor planets, Instrumentation, 01 natural sciences, Física Aplicada, 0103 physical sciences, medicine, Angular resolution, individual, Iris (anatomy), Adaptive optics, 010303 astronomy & astrophysics, individual: (7) Iris [Minor planets, asteroids], 0105 earth and related environmental sciences, Remote sensing, instrumentation, Physics, numerical [Methods], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], photometric [Techniques], Astronomy and Astrophysics, adaptive optics -methods, Light curve, adaptive optics [Instrumentation], numerical -techniques, medicine.anatomical_structure, Space and Planetary Science, Asteroid, Astrophysics::Earth and Planetary Astrophysics
Abstract: High angular resolution disc-resolved images of (7) Iris collected by VLT/SPHERE instrument are allowed for the detailed shape modelling of this large asteroid revealing its surface features. If (7) Iris did not suffer any events catastrophic enough to disrupt the body (which is very likely) by studying its topography, we might get insights into the early Solar system’s collisional history. When it comes to internal structure and composition, thoroughly assessing the volume and density uncertainties is necessary. In this work, we propose a method of uncertainty calculation of asteroid shape models based on light curve and adaptive optics (AO) images. We apply this method on four models of (7) Iris produced from independent Shaping Asteroids using Genetic Evolution and All-Data Asteroid Modelling inversion techniques and multiresolution photoclinometry by deformation. Obtained diameter uncertainties stem from both the observations from which the models were scaled and the models themselves. We show that despite the availability of high-resolution AO images, the volume and density of (7) Iris have substantial error bars that were underestimated in the previous studies., This work has been supported by the Czech Science Foundation through grant 20-08218S (JH, MB) and by the Charles University Research program No. UNCE/SCI/023. This work has been partially supported by Horizon 2020 grant no. 871149 ‘EPN-2024-RI’.
Published: 2020
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24. The Solar Orbiter Heliospheric Imager (SoloHI)

Author: J. J. Cerullo, Dennis Wang, Simon Plunkett, P. L. Lamy, S. Yerushalmi, A. P. Rouillard, J.-P. Halain, A. Thernisien, R. Baugh, D. H. Chua, R. A. Howard, Guillermo Stenborg, Robin C. Colaninno, M. T. Carter, Samuel Tun-Beltran, Spiros Patsourakos, R. Hagood, F. Auchere, Angelos Vourlidas, Sean Lynch, Dennis G. Socker, Richard A. Harrison, L. Smith, Volker Bothmer, Holly Gilbert, Greg Clifford, James Robert Janesick, Pierre Rochus, Mark Grygon, Clarence M. Korendyke, S. Koss, D. R. McMullin, Marco Velli, O. C. St. Cyr, A. Uhl, C. Mariano, P. C. Liewer, H. Dennison, K. Eisenhauer, N. Rich, T. Hunt, Jon A. Linker, Mark G. Linton, David Keller, John Robertson Tower, Adam Thurn, H. M. Maldonado, R. Farkas, Naval Research Laboratory (NRL), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Space Systems Research Corporation (SSRC), Silver Engineering, Inc., SRI International, Stinger Ghaffarian Technologies, Inc. (SGT, Inc.), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), University of California [Los Angeles] (UCLA), University of California (UC), Predictive Sciences Inc., Georg-August-University = Georg-August-Universität Göttingen, Centre Spatial de Liège (CSL), Université de Liège, European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), 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), Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC), Institut de recherche en astrophysique et planétologie (IRAP), 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), 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)-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), University of Ioannina, NASA Goddard Space Flight Center (GSFC), ASRC Federal Space and Defense, University of California, Georg-August-University [Göttingen], 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)-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), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), and 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)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Zodiacal light, 010504 meteorology & atmospheric sciences, Data products, business.industry, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], zodiacal dust, Sun, Astronomy and Astrophysics, telescopes, Astrophysics, Solar physics, 01 natural sciences, law.invention, Orbiter, Space and Planetary Science, law, 0103 physical sciences, Thermal, space vehicles, Aerospace engineering, business, 010303 astronomy & astrophysics, corona, 0105 earth and related environmental sciences
Abstract: Aims. We present the design and pre-launch performance of the Solar Orbiter Heliospheric Imager (SoloHI) which is an instrument prepared for inclusion in the ESA/NASA Solar Orbiter mission, currently scheduled for launch in 2020.Methods. The goal of this paper is to provide details of the SoloHI instrument concept, design, and pre-flight performance to give the potential user of the data a better understanding of how the observations are collected and the sources that contribute to the signal.Results. The paper discusses the science objectives, including the SoloHI-specific aspects, before presenting the design concepts, which include the optics, mechanical, thermal, electrical, and ground processing. Finally, a list of planned data products is also presented.Conclusions. The performance measurements of the various instrument parameters meet or exceed the requirements derived from the mission science objectives. SoloHI is poised to take its place as a vital contributor to the science success of the Solar Orbiter mission.
Published: 2020
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25. Saturn's Northern Aurorae at Solstice From HST Observations Coordinated With Cassini's Grand Finale

Author: Aikaterini Radioti, William S. Kurth, Wayne Pryor, Emma J. Bunce, P. Zarka, Renée Prangé, Baptiste Cecconi, Sarah V. Badman, Chihiro Tao, T. K. Kim, L. Lamy, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), National Institute of Information and Communications Technology (NICT), University of Alabama in Huntsville (UAH), Lancaster University, Department of Physics and Astronomy [Iowa City], University of Iowa [Iowa City], Central Arizona College, University of Leicester, Space Sciences, Technologies and Astrophysics Research Institute (STAR), Université de Liège, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), National Institute of Information and Communications Technology [Tokyo, Japan] (NICT), and Laboratoire de Physique Atmosphérique et Planétaire (LPAP)
Subjects: 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, 7. Clean energy, 01 natural sciences, Hubble space telescope, Saturn, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Solstice, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Low latitude, Astronomy, Solar illumination, Solar wind, Geophysics, [SDU]Sciences of the Universe [physics], 13. Climate action, Local time, Physics::Space Physics, General Earth and Planetary Sciences, Astrophysics::Earth and Planetary Astrophysics, Magnetohydrodynamics, Geology, Astrophysics - Earth and Planetary Astrophysics
Abstract: International audience; Throughout 2017, the Hubble Space Telescope (HST) observed the northern far-ultraviolet aurorae of Saturn at northern solstice, during the Cassini Grand Finale. These conditions provided a complete viewing of the northern auroral region from Earth and a maximal solar illumination, expected to maximize the ionosphere-magnetosphere coupling. In this study, we analyze 24 HST images concurrently with Cassini measurements of Saturn's Kilometric Radiation and solar wind parameters predicted by two MHD models. The aurorae reveal highly variable components, down to timescales of minutes, radiating 7 to 124 +/-11 GW. They include a nightside-shifted main oval, unexpectedly frequent and bright cusp emissions and a dayside low latitude oval. On average, these emissions display a strong Local Time dependence with two maxima at dawn and pre-midnight, the latter being newly observed and attributed to nightside injections possibly associated with solstice conditions. These results provide a reference frame to analyze Cassini in situ measurements, whether simultaneous or not.
Published: 2018
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26. Physical Attractiveness and Romantic Relationships: A Review

Author: L, Lamy , primary
Published: 2020
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27. Marx Multilevel Bipolar Modulator Dynamic Models for Load Transient Analysis

Author: L. Lamy Rocha, J. Fernando Silva, and Luis Redondo
Subjects: 010302 applied physics, Physics, Nuclear and High Energy Physics, business.industry, Electrical engineering, Topology (electrical circuits), Modular design, Condensed Matter Physics, Transient analysis, Topology, 01 natural sciences, 010305 fluids & plasmas, Pulse (physics), Dynamic models, mental disorders, 0103 physical sciences, Transient (oscillation), business, Voltage, Diode
Abstract: This paper presents generalized dynamic models for Marx derived multilevel half-bridge bipolar modulators. This high-voltage topology uses modular Marx multilevel converter diode (M3CD) cells to generate positive and negative (bipolar) pulses or unipolar (positive or negative voltage pulses). The developed models are tested in transient studies of pulse voltages and currents in the load. Simulation and experimental results are presented and compared.
Published: 2017
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28. Latitudinal beaming of Jovian decametric radio emissions as viewed from Juno and the Nançay Decameter Array

Author: George Hospodarsky, Alain Lecacheux, William S. Kurth, Masafumi Imai, John E. P. Connerney, L. Lamy, Steven Levin, Philippe Zarka, and Scott Bolton
Subjects: Physics, 010504 meteorology & atmospheric sciences, Spacecraft, business.industry, Astrophysics::High Energy Astrophysical Phenomena, Cyclotron, Astronomy, 01 natural sciences, Jovian, law.invention, Jupiter, Geophysics, 13. Climate action, law, Physics::Space Physics, 0103 physical sciences, Orbital motion, General Earth and Planetary Sciences, Astrophysics::Earth and Planetary Astrophysics, Maser, business, Longitude, Decametre, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: Two well-defined Jovian decametric radio arcs were observed at latitudinal separations of 11 ∘ –16 ∘ from the Juno spacecraft near Jupiter and the Nancay Decameter Array (NDA) at Earth on 17 May and 25 August 2016. These discrete arcs are from the so-called A source covering both Io-related and non-Io-related emissions. By measuring the wave arrival time at two distant observers with propagation time correction, the remaining delay times are 92.8 ± 1.3 min for the first arc and 116.0 ± 1.2 min for the second arc. This implies that both radio sources are not controlled by the orbital motion of Io but Jupiter's rotation itself. The geometrical information for Juno and NDA and the loss cone-driven electron cyclotron maser instability theory provide these radio sources that are located at about 173 ∘ ± 10 ∘ in system III longitude projected onto Jupiter's north surface and imply resonant electron energy ranges from 0.5 to 11 keV.
Published: 2017
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29. The H 3 + ionosphere of Uranus: decades-long cooling and local-time morphology

Author: L. Lamy, S. Miller, Luke Moore, Henrik Melin, Tom Stallard, Chihiro Tao, James O'Donoghue, Leigh N. Fletcher, N. Dello Russo, M. N. Chowdhury, L. M. Trafton, Ronald J. Vervack, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), 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)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], 010504 meteorology & atmospheric sciences, General Mathematics, Aeronomy, General Engineering, Uranus, General Physics and Astronomy, Astronomy, 01 natural sciences, Local time, 0103 physical sciences, Atmosphere of Uranus, Ionosphere, Spectroscopy, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract: The upper atmosphere of Uranus has been observed to be slowly cooling between 1993 and 2011. New analysis of near-infrared observations of emission from H 3 + obtained between 2012 and 2018 reveals that this cooling trend has continued, showing that the upper atmosphere has cooled for 27 years, longer than the length of a nominal season of 21 years. The new observations have offered greater spatial resolution and higher sensitivity than previous ones, enabling the characterization of the H 3 + intensity as a function of local time. These profiles peak between 13 and 15 h local time, later than models suggest. The NASA Infrared Telescope Facility iSHELL instrument also provides the detection of a bright H 3 + signal on 16 October 2016, rotating into view from the dawn sector. This feature is consistent with an auroral signal, but is the only of its kind present in this comprehensive dataset. This article is part of a discussion meeting issue ‘Advances in hydrogen molecular ions: H 3 + , H 5 + and beyond’.
Published: 2019
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30. Feasibility study of a thermal spectro-imager for space missions to small bodies

Author: Olivier Groussin, P. L. Lamy, and E. Brageot
Subjects: Solar System, Computer science, Detector, Thermal, Mechanical design, Baseline (configuration management), Space exploration, Remote sensing
Abstract: In this paper, we report on an on-going feasibility study of a thermal spectro-imager for future space missions to small bodies in the Solar System. Thanks to the recent development of uncooled micro-bolometer technology, we decided to use such a detector as a baseline for our study. For this feasibility study, we have defined four objectives using this detector to perform : (i) uncalibrated images, (ii) calibrated radiometric images, (iii) spectroscopic measurements, and (iv) a definition of the instrumental concept including the optical and mechanical design. Here we present our progress on the first two objectives of this work.
Published: 2019
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31. The H

Author: Henrik, Melin, L N, Fletcher, T S, Stallard, S, Miller, L M, Trafton, L, Moore, J, O'Donoghue, R J, Vervack, N, Dello Russo, L, Lamy, C, Tao, and M N, Chowdhury
Subjects: spectroscopy, Uranus, aeronomy, Articles, Research Article
Abstract: The upper atmosphere of Uranus has been observed to be slowly cooling between 1993 and 2011. New analysis of near-infrared observations of emission from H3+ obtained between 2012 and 2018 reveals that this cooling trend has continued, showing that the upper atmosphere has cooled for 27 years, longer than the length of a nominal season of 21 years. The new observations have offered greater spatial resolution and higher sensitivity than previous ones, enabling the characterization of the H3+ intensity as a function of local time. These profiles peak between 13 and 15 h local time, later than models suggest. The NASA Infrared Telescope Facility iSHELL instrument also provides the detection of a bright H3+ signal on 16 October 2016, rotating into view from the dawn sector. This feature is consistent with an auroral signal, but is the only of its kind present in this comprehensive dataset. This article is part of a discussion meeting issue ‘Advances in hydrogen molecular ions: H3+, H5+ and beyond’.
Published: 2019

32. Phase-curve analysis of comet 67P/Churyumov-Gerasimenko at small phase angles

Author: D. Bodewits, Marco Fulle, Monica Lazzarin, Jakob Deller, Giampiero Naletto, V. Da Deppo, Nafiseh Masoumzadeh, Stefano Debei, Mohamed Ramy El-Maarry, Detlef Koschny, Björn Davidsson, H. U. Keller, Cecilia Tubiana, J. J. Lopez-Moreno, Imre Toth, W-H. Ip, M. A. Barucci, Pedro Hasselmann, Gabriele Cremonese, Ludmilla Kolokolova, Sonia Fornasier, Colin Snodgrass, M. De Cecco, Pedro J. Gutiérrez, Xian Shi, Carsten Güttler, Ivano Bertini, Francesco Marzari, L. M. Lara, Stefano Mottola, Holger Sierks, R. Rodrigo, P. L. Lamy, J. L. Bertaux, Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, Department of Earth and Planetary Sciences [UCL/Birkbeck], Birkbeck College [University of London], DLR Institute of Planetary Research, German Aerospace Center (DLR), Institute for Astronomy [Edinburgh] (IfA), University of Edinburgh, Dipartimento di Fisica e Astronomia 'Galileo Galilei', Universita degli Studi di Padova, Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), CNR Istituto di Fotonica e Nanotecnologie [Padova] (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), IMPEC - 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), Centro de Astrobiologia [Madrid] (CAB), Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), International Space Science Institute [Bern] (ISSI), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Physics [Auburn], Auburn University (AU), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), CNR Institute for Photonics and Nanotechnologies (IFN), Department of Industrial Engineering [Padova], University of Trento [Trento], INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Space Science Institute [Macau] (SSI), Macau University of Science and Technology (MUST), Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig [Braunschweig], Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), PLANETO - 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), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), California Institute of Technology (CALTECH)-NASA, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), and Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig]
Subjects: Asteroiden und Kometen, Study phase, 010504 meteorology & atmospheric sciences, publications, bibliography, Comet, comets: general – comets: individual: 67P/Churyumov-Gerasimenko – techniques: photometric – techniques: image processing, Individual, Image processing, techniques: image processing, Coherent backscattering, Astrophysics, 7. Clean energy, 01 natural sciences, photometric [techniques], techniques: photometric, individual: 67P/Churyumov-Gerasimenko [Comets], 0103 physical sciences, Comets, publications, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, [PHYS]Physics [physics], Comets: individual: 67P/Churyumov-Gerasimenko, image processing [techniques], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Phase angle, bibliography - techniques, general [Comets], bibliography, Astronomy and Astrophysics, Phase curve, 67P/Churyumov-Gerasimenko - publications, bibliography - techniques, General - comets, Photometric - techniques, Computational physics, Comets: general, Wavelength, Space and Planetary Science, Phase ratio, 67P/Churyumov-Gerasimenko - publications, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Open Access funding provided by Max Planck Society., The Rosetta-OSIRIS images acquired at small phase angles in three wavelengths during the fly-by of the spacecraft on 9-10 April 2016 provided a unique opportunity to study the opposition effect on the surface of comet 67P/Churyumov-Gerasimenko (67P). Our goal is to study phase curves of the nucleus at small phase angles for a variety of surface structures to show the differences in their opposition effect and to determine which surface properties cause the differences.© N. Masoumzadeh et al. 2019, OSIRIS was built by a consortium of the Max-Planck-Institut fur Sonnensystemforschung, Gottingen, Germany; the CISAS University of Padova, Italy; the Laboratoire d'Astrophysique de Marseille, France; the Instituto de Astrofisica de Andalucia, CSIC, Granada, Spain; the Research and Scientific Support Department of the ESA, Noordwijk, Netherlands; the Instituto Nacional de Tecnica Aeroespacial, Madrid, Spain; the Universidad Politechnica de Madrid, Spain; the Department of Physics and Astronomy of Uppsala University, Sweden; and the Institut fur Datentechnik und Kommunikationsnetze der Technischen Universitat Braunschweig, Germany. The support of the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain (MEC), Sweden (SNSB), and the ESA Technical Directorate is gratefully acknowledged. We thank the Rosetta Science Operations Centre and the Rosetta Mission Operations Centre for the successful rendezvous with comet 67P/Churyumov-Gerasimenko. This research has made use of the USGS Integrated Software for Imagers and Spectrometers (ISIS). We gratefully acknowledge the developers of SPICE and NAIF/PDS resources. This research has made use of the scientific software shapeViewer www.comet-toolbox.com.L.K.acknowledges a support from the NASA SSW grant 80NSSC17K0731.
Published: 2019
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33. METIS, the Multi Element Telescope for Imaging and Spectroscopy: for the solar orbiter mission

Author: D. Moses, Marco Romoli, Michela Uslenghi, Luca Teriaca, Giampiero Naletto, M. G. Pelizzo, Silvano Fineschi, Federico Landini, P. L. Lamy, Maurizio Pancrazzi, V. Andretta, E. Battistelli, Piergiorgio Nicolosi, L. Poletto, Sami K. Solanki, Stefano Cesare, Ester Antonucci, F. Dangelo, Daniele Spadaro, V. Da Deppo, G. Nicolini, L. Zangrilli, and Mauro Focardi
Subjects: Telescope, Coronagraph, Orbiter, Cosmic Vision, law, Metis, Environmental science, Astronomy, Spectroscopy, Multi element, Corona, law.invention
Abstract: In 1999 the European solar scientific community proposed to ESA the Solar Orbiter (SO), a mission to explore the circumsolar region, to perform quasi helio-synchronous observations, and to obtain the first out-of-ecliptic imaging and spectroscopy of the solar poles and of the equatorial corona. Presently, SO is one of the three missions under study within the ESA Cosmic Vision 2015-2025 program, and a key ESA-NASA missions within the International Living with a Star Program. SO, to be launched on January 2017, is expected to provide major advances steps forward in understanding the Sun-heliosphere connection.
Published: 2019

34. Seven-Level Unipolar/Bipolar Pulsed Power Generator

Author: L. Lamy Rocha, Luis Redondo, and J. Fernando Silva
Subjects: Physics, Nuclear and High Energy Physics, Resistive touchscreen, Generator (category theory), business.industry, Capacitive sensing, 020208 electrical & electronic engineering, Electrical engineering, Order (ring theory), Hardware_PERFORMANCEANDRELIABILITY, 02 engineering and technology, Pulsed power, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, law.invention, Capacitor, law, 0103 physical sciences, Hardware_INTEGRATEDCIRCUITS, 0202 electrical engineering, electronic engineering, information engineering, business, Galvanic isolation, Hardware_LOGICDESIGN, Diode
Abstract: This paper shows how to use modular Marx multilevel converter diode ( $\text{M}^{3}$ CD) modules to apply unipolar or bipolar high-voltage pulses for pulsed power applications. The $\text{M}^{3}$ CD cells allow the assembly of a multilevel converter without needing complex algorithms and parameter measurement to balance the capacitor voltages. This paper also explains how to supply all the modular cells in order to ensure galvanic isolation between control circuits and power circuits. The experimental results for a generator with seven levels, and unipolar and bipolar pulses into resistive, inductive, and capacitive loads are presented.
Published: 2016
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35. Auroral Storm and Polar Arcs at Saturn—Final Cassini/UVIS Auroral Observations

Author: Jean-Claude Gérard, T. J. Bradley, Zhonghua Yao, L. Lamy, Wayne Pryor, William S. Kurth, Norbert Krupp, Aikaterini Radioti, Benjamin Palmaerts, Elias Roussos, Stanley W. H. Cowley, Emma J. Bunce, Denis Grodent, Laboratoire de Physique Atmosphérique et Planétaire (LPAP), Université de Liège, LPAP, Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), University of Leicester, Radio and Space Plasma Physics Group [Leicester] (RSPP), Max-Planck-Institut für Sonnensystemforschung (MPS), University of Iowa [Iowa City], Central Arizona College, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], 010504 meteorology & atmospheric sciences, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Plasma sheet, Astronomy, Magnetosphere, Storm, 01 natural sciences, Planetary Data System, Magnetic field, Geophysics, 13. Climate action, Saturn, Hubble space telescope, 0103 physical sciences, General Earth and Planetary Sciences, Polar, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: The Cassini/UVIS, MAG and RPWS data used in this study will be soon available through the Planetary Data System (https://pds.nasa.gov).
Published: 2018
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36. Optimized solid-state bipolar Marx modulador with resonant type droop compensation

Author: H. Canacsinh, V. Silva, J. P. M. Mendes, F. A. Silva, H. Bermaki, Luis Redondo, A. Semmak, and L. Lamy Rocha
Subjects: Physics, Pulse duration, Topology (electrical circuits), Inductor, Voltage droop, Compensation (engineering), law.invention, Capacitor, Control theory, law, RLC circuit, Compensation, Voltage
Abstract: Este trabalho foi financiado pelo Concurso Anual para Projetos de Investigação, Desenvolvimento, Inovação e Criação Artística (IDI&CA) 2016 do Instituto Politécnico de Lisboa. Código de referência IPL/2016/MBOCDTI_ISEL In this paper a voltage droop compensation based on a resonant circuit is proposed for the optimized solid-state bipolar Marx modulator. Keeping the modularity characteristics and the circuit topology, one auxiliary resonant stage was added to the existing Marx stages. The compensation concept consists of adding the auxiliary voltage to the output positive or negative pulse for voltage droop compensation. Simulation results are presented for five stages Marx circuit, 10% voltage droop, using 800 V per stage, 100 ps pulse duration at 50Hz frequency. info:eu-repo/semantics/publishedVersion
Published: 2018

37. A flux comparison of northern and southern Saturn kilometric radio bursts during southern summer

Author: Hajime Kita, Chihiro Tao, Tomoki Kimura, Atsushi Kumamoto, T. Tsuchiya, Caitriona M. Jackman, Akira Morioka, L. Lamy, Yasumasa Kasaba, Hiroaki Misawa, Daichi Maruno, and Baptiste Cecconi
Subjects: Physics, Plane (geometry), Magnetosphere of Saturn, Saturn, Flux, Energy flux, Astrophysics, Flux ratio
Abstract: The energy flux of the northern (N–) and southern (S–) Saturn kilometric radiation (SKR) bursts are statistically compared. We investigated the N– and S–SKR bursts from 2005 DOY 250 to 2006 DOY 200, when Cassini was close to the equatorial plane and RPWS could simultaneously observe both N– and S–SKR. We identified 38 burst events, and compared their flux from southern (summer–side) and northern (winter–side) hemispheres. In the main band (100–400 kHz), S–SKR bursts from the summer–side hemisphere were 5–6 times stronger than the N–SKR bursts from the winter–side. This is not far from the flux ratio in the non-burst status. In the low-frequency extension (10–50 kHz) of SKR bursts, this ratio is smaller, about 2–3 times.
Published: 2018
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38. A model of the Jovian internal field derived from in-situ and auroral constraints

Author: F. Bagenal, S. L. G. Hess, B. Bonfond, and L. Lamy
Subjects: Jupiter, Physics, Field (physics), Position (vector), Computation, Physics::Space Physics, Orbit (dynamics), Astrophysics::Earth and Planetary Astrophysics, Square (algebra), Jovian, Computational physics, Magnetic field
Abstract: The internal magnetic field of Jupiter is known to be highly multi-polar, not only from the direct measurements performed by the Voyager and Pioneer probes but also from the unusually complex shape of the northern auroral oval. The limited amount of data obtained from the Voyager and Pioneer flybys do not permit accurate determination of the topology of the magnetic field, as they barely constrain, even the octupole contribution to the field. This does not allow one to reproduce the position of the auroras nor satisfactorily explain the shape and frequency range of the Jovian radio arcs. Successive attempts have been made to constrain the higher– degree field using the position of the Io auroral footprint where the auroras are due to currents generated close to Io and carried along the magnetic field lines. Thus, the auroral spots should map to Io’s orbit. VIPAL, the latest model of this kind is a 5th degree model. However, the VIPAL model was limited by three factors: the main constraints come from a unique L-shell, the difficulty of mixing Jovigraphic and magnetic data, and the non-linearity of the problem. These issues lead to numerically demanding computations, with the scale of computation increasing as the square of the model degree. We have developed a new method for computing the magnetic field using in-situ and auroral constraints (ISaAC) which we have applied to the computation of the Jovian magnetic field, based on Voyager, Pioneer, Galileo magnetic measurements and constrained by Io’s, Europa’s and Ganymede’s auroral footprint locations.
Published: 2018
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39. Analysis of Jovian low-frequency radio emissions based on stereoscopic observations with Juno and Earth-based radio telescopes

Author: L. Lamy, John E. P. Connerney, Scott Bolton, Masafumi Imai, A. Lecacheux, Baptiste Cecconi, Steve Levin, William S. Kurth, D. A. Gurnett, George Hospodarsky, and P. Zarka
Subjects: Physics, Radio telescope, law, Astronomy, Stereoscopy, Low frequency, Jovian, Earth (classical element), law.invention
Published: 2018
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40. On deviations from free-radial outflow in the inner coma of comet 67P/Churyumov–Gerasimenko

Author: Olivier Groussin, Björn Davidsson, Giampiero Naletto, S. Fornasier, Cecilia Tubiana, Horst Uwe Keller, P. L. Lamy, Michael Küppers, J.F. Wu, Hans Rickman, M. A. Barucci, W-H. Ip, Ekkehard Kührt, Stubbe F. Hviid, Selina-Barbara Gerig, L. M. Lara, C. C. Su, Marco Fulle, Nilda Oklay, R. Rodrigo, Monica Lazzarin, Stefano Mottola, Jean-Baptiste Vincent, V. Da Deppo, Laurent Jorda, Jörg Knollenberg, P. J. Gutierrez, Stefano Debei, Frank Scholten, G. Cremonese, M. De Cecco, Holger Sierks, Frank Preusker, J. L. Bertaux, Cesare Barbieri, Jakob Deller, Raphael Marschall, Dennis Bodewits, J. J. Lopez Moreno, Ivano Bertini, Detlef Koschny, Nicolas Thomas, Carsten Güttler, Jessica Agarwal, Imre Tóth, Francesco Marzari, J.-R. Kramm, Swiss National Science Foundation, European Commission, Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Università degli Studi di Padova = University of Padua (Unipd), Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), INAF - Osservatorio Astronomico di Trieste (OAT), Istituto Nazionale di Astrofisica (INAF), Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Operations Department (ESAC), European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Department of Mechanical Engineering [NCTU], National Chiao Tung University (NCTU), Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), 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), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Dipartimento di Fisica e Astronomia 'Galileo Galilei', 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), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), International Space Science Institute [Bern] (ISSI), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Department of Physics and Astronomy [Uppsala], Uppsala University, 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)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Padova (OAPD), Laboratory for Ultraviolet and X-ray Optical Research [Padova] (LUXOR), CNR Institute for Photonics and Nanotechnologies (IFN), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)-National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), University of Trento [Trento], Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Universität Bern [Bern], Institute of Space Science [Taiwan], Max-Planck-Institut für Sonnensystemforschung (MPS), Max Planck Institute for Solar System Research (MPS), DLR Institute of Planetary Research, German Aerospace Center (DLR), University of Bern (UBERN), International Space Science Institute (ISSI), Centro Interdipartimentale di Studi e Attività Spaziali 'Giuseppe Colombo', Università di Padova (CISAS), Department of Astronomy, University of Maryland, Jet Propulsion Laboratory, California Institute of Technology (JPL), INAF - Osservatorio Astronomico, Via Tiepolo 11, 34014 Trieste, Italy, Graduate Institute of Astronomy, Institute for Geophysics and Extraterrestrial Physics, Technische Universität Braunschweig, Science Operations Department, European Space Astronomy Centre/ESA, P.O. Box 78, 28691 Villanueva de la Canada, Madrid, Spain, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Department of Physics, National Tsing Hua University, Konkoly Observatory, Research Center for Astronomy and Earth Sciences, Max-Planck-Institut fur Sonnensystemforschung, Justus-von-Liebig-Weg, 3, 37077 Gottingen, Germany, Department of Physics and Astronomy, University of Padova, Vicolo dell'Osservatorio 3, 35122 Padova, Italy, 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), European Space Agency (ESA), Space Research Center, Polish Academy of Sciences (Warsaw), Observatoire de Paris, Université Paris sciences et lettres (PSL), CNR-IFN UOS Padova LUXOR, Università di Trento (UNITN), Instituto de Astrofisica de Andalucia, CSIC (IAA), Dipartimento di Fisica, Università di Padova, Universita degli Studi di Padova, California Institute of Technology (CALTECH)-NASA, European Space Agency (ESA)-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)-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), Consiglio Nazionale delle Ricerche [Roma] (CNR)-Consiglio Nazionale delle Ricerche [Roma] (CNR), Technische Universität Braunschweig [Braunschweig], 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), IMPEC - LATMOS, Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), Polska Akademia Nauk (PAN), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Consejo Superior de Investigaciones Científicas [Spain] (CSIC)
Subjects: 67P/Churyumov-Gerasimenko, Brightness, 010504 meteorology & atmospheric sciences, Infrared, 67P/Churyumov–Gerasimenko, Astrophysics, Dust, Inner coma, OSIRIS, Rosetta, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Magnetosphere particle motion, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 520 Astronomy, Astronomy and Astrophysics, 620 Engineering, Particle acceleration, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Outflow, Direct simulation Monte Carlo, Astrophysics::Earth and Planetary Astrophysics, Test particle, Impact parameter, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: This article is available under the Creative Commons CC-BY-NC-ND license and permits non-commercial use of the work as published, without adaptation or alteration provided the work is fully attributed. For commercial reuse, permission must be requested below., The Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) onboard the European Space Agency's Rosetta spacecraft acquired images of comet 67P/Churyumov–Gerasimenko (67P) and its surrounding dust coma starting from May 2014 until September 2016. In this paper we present methods and results from analysis of OSIRIS images regarding the dust outflow in the innermost coma of 67P. The aim is to determine the global dust outflow behaviour and place constraints on physical processes affecting particles in the inner coma. We study the coma region right above the nucleus surface, spanning from the nucleus centre out to a distance of about 50 km comet centric distance (approximately 25 average comet radii). We primarily adopt an approach used by Thomas and Keller (1990) to study the dust outflow. We present the effects on azimuthally-averaged values of the dust reflectance of non-radial flow and non-point-source geometry, acceleration of dust particles, sublimation of icy dust particles after ejection from the surface, dust particle fragmentation, optical depth effects and the influence of gravitationally bound particles. All of these physical processes could modify the observed distribution of light scattered by the dust coma. In the image analysis, profiles of azimuthally averaged dust brightness as a function of impact parameter b (azimuthal average, “Ā-curve”) were fitted with a simple function that best fits the shape of our profile curves (f(b;u,v,w,z)=u/b+wb+z). The analytical fit parameters (u, v, w, z), which hold the key information about the dust outflow behaviour, were saved in a comprehensive database. Through statistical analysis of these information, we show that the spatial distribution of dust follows free-radial outflow behaviour (i.e. force-free radial outflow with constant velocity) beyond distances larger than ∼11.9 km from the comet centre, which corresponds to a relative distance of about 6 average comet radii from the comet centre. Hence, we conclude that beyond this distance, and on average, fragmentation and gravitationally bound particles are negligible processes in determining the optically scattered light distribution in the innermost coma. Closer to the nucleus we observe dust outflow behaviour that deviates from free-radial outflow. A comparison of our result profiles with numerical models using a Direct Simulation Monte Carlo (DSMC) approach with dust particle distributions calculated using a test particle approach has been used to demonstrate the influence of a complex shape and particle acceleration on the azimuthal average profiles. We demonstrate that, while other effects such as fragmentation or sublimation of dust particles cannot be ruled out, acceleration of the dust particles and effects arising from the shape of the irregular nucleus (non-point source geometry) are sufficient to explain the observed dust outflow behaviour from image data analysis. As a by-product of this work, we have calculated “Afρ” values for the 1/r regime. We found a peak in the coma activity in terms of Afρ (normalised to a phase angle of 90°) of ∼210 cm 20 days after perihelion. Furthermore, based on simplified models of particle motion within bound orbits, it is shown that limits on the total cross-sectional area of bound particles might be derived through further analysis. An example is given. © 2018 The Authors, The team from the University of Bern is supported through the Swiss National Science Foundation and through the NCCR PlanetS. The project has also received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 686709. This work was supported by the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract number 16.0008-2. The opinions expressed and arguments employed herein do not necessarily reflect the official views of the Swiss Government.
Published: 2018
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41. Regional unit definition for the nucleus of comet 67P/Churyumov-Gerasimenko on the SHAP7 model

Author: Holger Sierks, J.-B. Vincent, F. Preusker, Giampiero Naletto, Francesco Marzari, Sonia Fornasier, Stubbe F. Hviid, M. A. Barucci, P. J. Gutierrez, Carsten Güttler, J. J. Lopez-Moreno, Jörg Knollenberg, Ivano Bertini, Stefano Debei, V. Da Deppo, P. L. Lamy, Frank Scholten, Detlef Koschny, Björn Davidsson, W-H. Ip, Marco Fulle, Nicolas Thomas, M. R. El Maarry, Cecilia Tubiana, Monica Lazzarin, Ekkehard Kührt, L. M. Lara, Raphael Marschall, J. L. Bertaux, H. U. Keller, Dennis Bodewits, R. Rodrigo, Laurent Jorda, G. Cremonese, M. De Cecco, P. Theologou, Olivier Groussin, ITA, USA, GBR, FRA, DEU, Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), 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), International Space Science Institute [Bern] (ISSI), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Università degli Studi di Padova = University of Padua (Unipd), Dipartimento di Fisica e Astronomia 'Galileo Galilei', CNR Istituto di Fotonica e Nanotecnologie [Padova] (IFN), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), 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)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), 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), Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), CNR Institute for Photonics and Nanotechnologies (IFN), Department of Industrial Engineering [Padova], University of Trento [Trento], INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), Space Science Institute [Macau] (SSI), Macau University of Science and Technology (MUST), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Universität Bern [Bern], 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), Universita degli Studi di Padova, Consiglio Nazionale delle Ricerche [Roma] (CNR), Max-Planck-Institut für Sonnensystemforschung (MPS), European Space Agency (ESA)-European Space Agency (ESA), California Institute of Technology (CALTECH)-NASA, 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), Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), IMPEC - LATMOS, Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Technische Universität Braunschweig [Braunschweig], Swiss National Science Foundation, European Commission, and State Secretariat for Education, Research and Innovation (Switzerland)
Subjects: 67P/Churyumov-Gerasimenko, Morphology, Surface (mathematics), 010504 meteorology & atmospheric sciences, Comet, Geometry, Surface finish, Table (information), 01 natural sciences, Nucleus, Computer graphics, Rosetta, 0103 physical sciences, medicine, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Subdivision, Astronomy and Astrophysics, Space and Planetary Science, business.industry, 520 Astronomy, 620 Engineering, medicine.anatomical_structure, es, [SDU]Sciences of the Universe [physics], business, Unit (ring theory), Geology
Abstract: Open Acces publication. This article is available under the Creative Commons CC-BY-NC-ND license and permits non-commercial use of the work as published, without adaptation or alteration provided the work is fully attributed., The previously defined regions on the nucleus of comet 67P/Churyumov-Gerasimenko have been mapped back onto the 3D SHAP7 model of the nucleus (Preusker et al., 2017). The resulting regional definition is therefore self-consistent with boundaries that are well defined in 3 dimensions. The facets belonging to each region are provided as supplementary material. The shape model has then been used to assess inhomogeneity of nucleus surface morphology within individual regions. Several regions show diverse morphology. We propose sub-division of these regions into clearly identifiable units (sub-regions) and a comprehensive table is provided. The surface areas of each sub-region have been computed and statistics based on grouping of unit types are provided. The roughness of each region is also provided in a quantitative manner using a technique derived from computer graphics applications. The quantitative method supports the sub-region definition by showing that differences between sub-regions can be numerically justified.© 2018 The Authors, The team from the University of Bern is supported through the Swiss National Science Foundation and through the NCCR PlanetS. The project has also received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 686709. This work was supported by the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract number 16.0008-2.
Published: 2018
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42. METIS, the Multi Element Telescope for Imaging and Spectroscopy: an instrument proposed for the solar orbiter mission

Author: George A. Doschek, Luca Poletto, Stefano Cesare, Marco Romoli, Daniele Spadaro, Silvio Giordano, Sami K. Solanki, P. L. Lamy, D. Moses, Silvano Fineschi, Ester Antonucci, Luca Teriaca, Giampiero Naletto, Vincenzo Andretta, Angela Ciaravella, Jeffrey S. Newmark, and L. Zangrilli
Subjects: Physics, Spectrometer, Applied Mathematics, Extreme ultraviolet lithography, Astronomy, Solar radius, 02 engineering and technology, Condensed Matter Physics, 01 natural sciences, Corona, law.invention, 010309 optics, Telescope, Orbiter, law, Electronic, Optical and Magnetic Materials, Electrical and Electronic Engineering, Extreme ultraviolet, 0103 physical sciences, Electronic, 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, Optical and Magnetic Materials, Coronagraph
Abstract: METIS, the Multi Element Telescope for Imaging and Spectroscopy, is an instrument proposed to the European Space Agency to be part of the payload of the Solar Orbiter mission. The instrument design has been conceived for performing extreme ultraviolet (EUV) spectroscopy both on the solar disk and off-limb, and near-Sun coronagraphy and spectroscopy. The proposed instrument suite consists of three different interconnected elements, COR, EUS and SOCS, sharing the same optical bench, electronics, and S/C heat shield aperture. COR is a visible-EUV multiband coronagraph based on a classical externally occulted design. EUS is the component of the METIS EUV disk spectrometer which includes the telescope and all the related mechanisms. Finally, SOCS is the METIS spectroscopic component including the dispersive system and the detectors. The capability of inserting a small telescope collecting coronal light has been added to perform also EUV coronal spectroscopy. METIS can simultaneously image the visible and ultraviolet emission of the solar corona and diagnose, with unprecedented temporal coverage and space resolution the structure and dynamics of the full corona in the range from 1.2 to 3.0 (1.6 to 4.1) solar radii (R, measured from Sun centre) at minimum (maximum) perihelion during the nominal mission. It can also perform spectroscopic observations of the solar disk and out to 1.4 R􀁾 within the 50-150 nm spectral region, and of the geo-effective coronal region 1.7-2.7 R within the 30-125 nm spectral band.
Published: 2017
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43. ASPIICS: a giant, white light and emission line coronagraph for the ESA proba-3 formation flight mission

Author: Andrei Zhukov, Kanaris Tsinganos, R. A. Howard, Petr Heinzel, Silvano Fineschi, Sergey Kuzin, Luc Damé, Werner Schmutz, Joseph M. Davila, S. Vives, Werner Curdt, Jean-Marc Defise, and P. L. Lamy
Subjects: Physics, Spacecraft, business.industry, Optical instrument, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Solar radius, Corona, law.invention, Solar wind, Optics, law, Physics::Space Physics, Coronal mass ejection, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, business, Coronagraph, Chromosphere
Abstract: Classical externally-occulted coronagraphs are presently limited in their performances by the distance between the external occulter and the front objective. The diffraction fringe from the occulter and the vignetted pupil which degrades the spatial resolution prevent useful observations of the white light corona inside typically 2-2.5 solar radii (Rsun). Formation flying offers and elegant solution to these limitations and allows conceiving giant, externally-occulted coronagraphs using a two-component space system with the external occulter on one spacecraft and the optical instrument on the other spacecraft at a distance of hundred meters [1, 2]. Such an instrument ASPIICS (Association de Satellites Pour l’Imagerie et l’Interferometrie de la Couronne Solaire) has been selected by the European Space Agency (ESA) to fly on its PROBA-3 mission of formation flying demonstration which is presently in phase B (Fig. 1). The classical design of an externally-occulted coronagraph is adapted to the formation flying configuration allowing the detection of the very inner corona as close as ∼0.04 solar radii from the solar limb. By tuning the position of the occulter spacecraft, it may even be possible to reach the chromosphere and the upper part of the spicules [3]. ASPIICS will perform (i) high spatial resolution imaging of the continuum KpF corona in photometric and polarimetric modes, (ii) high spatial resolution imaging of the E-corona in two coronal emission lines (CEL): Fe XIV and He I D3, and (iii) two-dimensional spectrophotometry of the Fe XIV emission line. ASPIICS will address the question of the coronal heating and the role of waves by characterizing propagating fluctuations (waves and turbulence) in the solar wind acceleration region and by looking for oscillations in the intensity and Doppler shift of spectral lines. The combined imaging and spectral diagnostics capabilities available with ASPIICS will allow mapping the velocity field of the corona both in the sky plane (directly on the images) and along the line-of-sight by measuring the Doppler shifts of emission lines in an effort to determine how the different components of the solar wind, slow and fast are accelerated. With a possible launch in 2014, ASPIICS will observe the corona during the maximum of solar activity, insuring the detection of many Coronal Mass Ejections (CMEs). By rapidly alternating high-resolution imaging and spectroscopy, CMEs will be thoroughly characterized.
Published: 2017
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44. ASPIICS/PROBA-3 formation flying solar coronagraph: Stray light analysis and optimization of the occulter

Author: Melanie Venet, Alexandra Mazzoli, Federico Landini, Giuseppe Massone, S. Vives, P. L. Lamy, and Marco Romoli
Subjects: Physics, Spacecraft, business.industry, Stray light, Aperture, Corona, law.invention, Entrance pupil, Telescope, symbols.namesake, Optics, law, symbols, Arago spot, business, Coronagraph
Abstract: The “Association de Satellites Pour l'Imagerie et l'Interferometrie de la Couronne Solaire”, ASPIICS, selected by ESA for the PROBA-3 mission, heralds the next generation of coronagraph for solar research, exploiting formation flying to gain access to the inner corona under eclipse-like conditions for long periods of time. A detailed description of the ASPIICS instrument and of its scientific objectives can be found in [1]. ASPIICS is distributed on the two PROBA 3 spacecrafts (S/C) separated by 150 m. The coronagraph optical assembly is hosted by the “coronagraph S/C” protected from direct solar disk light by the occulting disk on the “occulter S/C”. The most critical issue in the design of a solar coronagraph is the reduction of the stray light due to the diffraction and scattering of the solar disk light by the occulter, the aperture and the optics. In the present article, we deal with two of these issues: - The analysis of the stray light inside the telescope. - The optimization of the external occulter edge, in order to eliminate the Poisson spot behind the occulter and to lower the stray light level going through the entrance pupil of the telescope. This work was performed in the framework of the ESA STARTIGER program which took place at the Laboratoire d’Astrophysique de Marseille (LAM) during a 6-month period from September 2009 to March 2010. In general, it is a very complicated task to combine the above two stray light issues together in the simulation and design phase as it requires to consider the propagation inside the telescope of the light diffracted by the external occulter. Actually, the present literature only reports diffraction calculations performed for simple occulting systems (i.e., two disks and serrated disk). A more pragmatic approach, also driven by the tight schedule of the STARTIGER program, is to separate the two contributions, and perform two different stray light analyses. This paper is dedicated to the description of both analyses: in particular, the first part is dedicated to the evaluation of the stray light inside the telescope, assuming a simple disk as occulter, and a preliminary baffle design is presented; the second part describes the investigation on the geometry of the external occulter, with a detailed description of the laboratory setup that has been designed and implemented to compare together several types of occulting systems.
Published: 2017
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45. Seasonal Mass Transfer on the Nucleus of Comet 67P/Chuyumov-Gerasimenko

Author: Frank Preusker, Wing-Huen Ip, Laurent Jorda, J. J. López-Moreno, Carsten Güttler, H. Rickman, Michael Küppers, Stubbe F. Hviid, Holger Sierks, Katharina A. Otto, G. Cremonese, M. A. Barucci, J. Deller, Ivano Bertini, Nilda Oklay, P. J. Gutierrez, Michael F. A'Hearn, Marc Hofmann, Nicolas Thomas, Frank Scholten, Jessica Agarwal, P. L. Lamy, Maurizio Pajola, V. Da Deppo, M. De Cecco, J.-R. Kramm, Cecilia Tubiana, Francesco Marzari, Imre Toth, Marco Fulle, Cesare Barbieri, Xian Shi, Stefano Mottola, Yuri V. Skorov, B. J. R. Davidsson, J. L. Bertaux, D. Koschny, Giampiero Naletto, Stefan Schröder, Monica Lazzarin, Dennis Bodewits, Jean-Baptiste Vincent, Sonia Fornasier, H. U. Keller, Jörg Knollenberg, Rafael Rodrigo, Ekkehard Kührt, L. M. Lara, Olivier Groussin, Stefano Debei, DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Department of Physics and Astronomy [Uppsala], Uppsala University, NASA Ames Research Center (ARC), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), Dipartimento di Fisica e Astronomia 'Galileo Galilei', 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), Centro de Astrobiologia [Madrid] (CAB), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), International Space Science Institute [Bern] (ISSI), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), 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), 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), INAF - Osservatorio Astronomico di Trieste (OAT), Istituto Nazionale di Astrofisica (INAF), CNR Institute for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), Department of Industrial Engineering [Padova], University of Trento [Trento], Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institute of Space Science [Taiwan], National Central University [Taiwan] (NCU), Operations Department (ESAC), European Space Astronomy Centre (ESAC), European Space Agency (ESA)-European Space Agency (ESA), Department of Information Engineering [Padova] (DEI), Center for Space and Habitability (CSH), University of Bern, Physikalisches Institut [Bern], Universität Bern [Bern], Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Università degli Studi di Padova = University of Padua (Unipd), 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), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Agence Spatiale Européenne = European Space Agency (ESA), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Universität Bern [Bern] (UNIBE), and ITA
Subjects: Asteroiden und Kometen, 67P/Churyumov-Gerasimenko, 010504 meteorology & atmospheric sciences, Comets: individual (67P/Churyumov-Gerasimenko), Methods: data analysis, Comet, Data analysis, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Radiation, Granular material, 01 natural sciences, comet, Mass transfer, individual 67P/Churyumov-Gerasimenko, 0103 physical sciences, medicine, Comets, 010303 astronomy & astrophysics, Southern Hemisphere, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), [PHYS]Physics [physics], [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 520 Astronomy, Planetengeodäsie, Astronomy, Astronomy and Astrophysics, 620 Engineering, medicine.anatomical_structure, 13. Climate action, Space and Planetary Science, Sublimation (phase transition), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Nucleus, Water vapor, Astrophysics - Earth and Planetary Astrophysics
Abstract: We collect observational evidence that supports the scheme of mass transfer on the nucleus of comet 67P/Churyumov-Gerasimenko. The obliquity of the rotation axis of 67P causes strong seasonal variations. During perihelion the southern hemisphere is four times more active than the north. Northern territories are widely covered by granular material that indicates back fall originating from the active south. Decimetre sized chunks contain water ice and their trajectories are influenced by an anti-solar force instigated by sublimation. OSIRIS observations suggest that up to 20 % of the particles directly return to the nucleus surface taking several hours of travel time. The back fall covered northern areas are active if illuminated but produce mainly water vapour. The decimetre chunks from the nucleus surface are too small to contain more volatile compounds such as CO 2 or CO. This causes a north-south dichotomy of the composition measurements in the coma. Active particles are trapped in the gravitational minimum of Hapi during northern winter. They are "shock frozen" and only reactivated when the comet approaches the sun after its aphelion passage. The insolation of the big cavity is enhanced by self-heating, i. e. reflection and IR radiation from the walls. This, together with the pristinity of the active back fall, explains the early observed activity of the Hapi region. Sobek may be a role model for the consolidated bottom of Hapi. Mass transfer in the case of 67P strongly influences the evolution of the nucleus and the interpretation of coma measurements., Comment: 17 pages, 20 figures
Published: 2017
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46. Modeling Marx generators for maximum pulse repetition rate estimation

Author: Luis Redondo, L. Lamy Rocha, J. Fernando Silva, T. Luciano, and H. Canacsinh
Subjects: 010302 applied physics, Repetition (rhetorical device), Semiconductor device modeling, 01 natural sciences, Capacitance, Marx generator, 010305 fluids & plasmas, Pulse (physics), law.invention, Generator (circuit theory), Capacitor, Hardware_GENERAL, Control theory, law, 0103 physical sciences, Voltage, Mathematics
Abstract: This paper presents a generalized n stage dynamic model for unipolar semiconductor based Marx generators. The model is tailored for the capacitors charging mode to enable the estimation of the maximum pulse repetition rate of the n stage generator. The maximum pulse repetition rate for the n stage Marx generator can be calculated as a function of the number n of stages, and of the voltage decay allowed in each capacitor (usually less than 10%). Furthermore, given a needed pulse repetition rate the model can estimate the optimum number of stages (n) so that the working voltage of each stage can be selected. Simulation results for a ten-stage (n=10) positive output Marx generators are presented and discussed.
Published: 2017
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47. Regional surface morphology of comet 67P/Churyumov-Gerasimenko from Rosetta/OSIRIS images: The southern hemisphere (Corrigendum)

Author: Monica Lazzarin, Laurent Jorda, J. B. Vincent, Cesare Barbieri, N. Thomas, Lorenza Giacomini, Olivier Groussin, S. Fornasier, Simone Marchi, B. J. R. Davidsson, A. Gracia-Berná, Antoine Pommerol, G. Cremonese, A. T. Auger, Raphael Marschall, Detlef Koschny, Matteo Massironi, P. J. Gutierrez, Stubbe F. Hviid, Holger Sierks, Cecilia Tubiana, Michael Küppers, F. Scholten, R. Rodrigo, Maurizio Pajola, N. Oklay, Mohamed Ramy El-Maarry, Ivano Bertini, J. J. Lopez Moreno, Géza Kovács, Hans Rickman, M. A. Barucci, W-H. Ip, J.-R. Kramm, Marco Fulle, P. L. Lamy, M. De Cecco, V. Da Deppo, Sebastien Besse, F. Preusker, Carsten Güttler, Giampiero Naletto, Francesco Marzari, H. U. Keller, M. F. A'Hearn, J. L. Bertaux, J.-C. Lee, Dennis Bodewits, Jörg Knollenberg, E. Kuehrt, L. M. Lara, Stefano Debei, Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), NASA Ames Research Center (ARC), Department of Atmospheric Sciences [Taoyuan City], National Central University [Taiwan] (NCU), Dipartimento di Geoscienze [Padova], Università degli Studi di Padova = University of Padua (Unipd), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Solar System Exploration Research Virtual Institute (SSERVI), Southwest Research Institute [Boulder] (SwRI), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), ESA Scientific Support Office, Agence Spatiale Européenne = European Space Agency (ESA), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Dipartimento di Fisica e Astronomia 'Galileo Galilei', INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), 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), Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Department of Physics and Astronomy [Uppsala], Uppsala University, International Space Science Institute [Bern] (ISSI), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, 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), 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), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), CNR Institute for Photonics and Nanotechnologies (IFN), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Università degli Studi di Trento (UNITN), Department of Mechanical Engineering [Padova], Department of Industrial Engineering [Padova], Università degli Studi di Padova = University of Padua (Unipd)-Università degli Studi di Padova = University of Padua (Unipd), INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institute of Astronomy [Taiwan] (IANCU), Department of Information Engineering [Padova] (DEI), CNR Istituto di Fotonica e Nanotecnologie [Padova] (IFN), Universität Bern [Bern], Universita degli Studi di Padova, European Space Agency (ESA), Max-Planck-Institut für Sonnensystemforschung (MPS), 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), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), Consiglio Nazionale delle Ricerche [Roma] (CNR), Universita degli Studi di Padova-Universita degli Studi di Padova, Max Planck Institute for Solar System Research (MPS), and California Institute of Technology (CALTECH)-NASA
Subjects: Asteroiden und Kometen, 67P/Churyumov-Gerasimenko, 010504 meteorology & atmospheric sciences, 530 Physics, Comet, 01 natural sciences, Astrobiology, 0103 physical sciences, Rosetta, comets, OSIRIS, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Physics, biology, 520 Astronomy, Planetengeodäsie, Astronomy, Astronomy and Astrophysics, 500 Science, biology.organism_classification, 620 Engineering, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Osiris, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: International audience
Published: 2017
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48. The aurorae of Uranus past equinox

Author: Nikolai V. Pogorelov, Stan W. H. Cowley, Henrik Melin, Nicholas Achilleos, Chihiro Tao, L. Lamy, T. K. Kim, Kirk C. Hansen, Renée Prangé, Sarah V. Badman, Patrick Guio, Tom Stallard, 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), University of Michigan [Ann Arbor], University of Michigan System, National Institute of Information and Communications Technology [Tokyo, Japan] (NICT), University of Leicester, University College of London [London] (UCL), Lancaster University, and University of Alabama in Huntsville (UAH)
Subjects: Physics, 010504 meteorology & atmospheric sciences, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astrophysics::High Energy Astrophysical Phenomena, Uranus, Astronomy, Magnetosphere, Equinox, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Solar wind, Geophysics, 13. Climate action, Space and Planetary Science, Planet, 0103 physical sciences, Physics::Space Physics, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Interplanetary spaceflight, Longitude, 010303 astronomy & astrophysics, Space Telescope Imaging Spectrograph, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences
Abstract: 10 pages, 5 Figures; International audience; The aurorae of Uranus were recently detected in the far ultraviolet with the Hubble Space Telescope (HST) providing a new, so far unique, means to remotely study the asymmetric Uranian magnetosphere from Earth. We analyze here two new HST Uranus campaigns executed in September 2012 and November 2014 with different temporal coverage and under variable solar wind conditions numerically predicted by three different MHD codes. Overall, the HST images taken with the Space Telescope Imaging Spectrograph reveal auroral emissions in three pairs of successive images (one pair acquired in 2012 and two in 2014), hence 6 additional auroral detections in total, including the most intense Uranian aurorae ever seen with HST. The detected emissions occur close the expected arrival of interplanetary shocks. They appear as extended spots at southern latitudes, rotating with the planet. They radiate 5–24 kR and 1.3-8.8 GW of ultraviolet emission from H2, last for tens of minutes and vary on timescales down to a few seconds. Fitting the 2014 observations with model auroral ovals constrains the longitude of the southern (northern) magnetic pole to 104 ± 26° (284 ± 26°) in the Uranian Longitude System. We suggest that the Uranian near-equinoctial aurorae are pulsed cusp emissions possibly triggered by large-scale magnetospheric compressions.
Published: 2017
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49. The Subsurface Structure and Density of Cometary Nuclei

Author: P. L. Lamy, A. Herique, and I. Toth
Published: 2017
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50. Surface evolution of the Anhur region on comet 67P/Churyumov-Gerasimenko from high-resolution OSIRIS images

Author: R. Rodrigo, M. De Cecco, Stefano Debei, P. J. Gutierrez, Ivano Bertini, J. M. Sunshine, P. L. Lamy, Detlef Koschny, S. Fornasier, Xian Shi, Laurent Jorda, G. Cremonese, J. B. Vincent, Marco Fulle, Imre Tóth, Maurizio Pajola, M. L. Lara, J. L. Bertaux, Sabrina Ferrari, C. Güttler, V. Da Deppo, Dennis Bodewits, M. A. Barucci, W-H. Ip, Jakob Deller, Holger Sierks, Clement Feller, Stefano Mottola, Monica Lazzarin, Alice Lucchetti, Cecilia Tubiana, J. J. Lopez Moreno, B. J. R. Davidsson, Horst Uwe Keller, Giampiero Naletto, Francesco Marzari, Pedro Hasselmann, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-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, DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, Dipartimento di Fisica e Astronomia 'Galileo Galilei', CNR Istituto di Fotonica e Nanotecnologie [Padova] (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), IMPEC - 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), Centro de Astrobiologia [Madrid] (CAB), Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), International Space Science Institute [Bern] (ISSI), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS), Department of Physics [Auburn], Auburn University (AU), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), CNR Institute for Photonics and Nanotechnologies (IFN), Department of Mechanical Engineering [Padova], Department of Industrial Engineering [Padova], Universita degli Studi di Padova-Universita degli Studi di Padova, University of Trento [Trento], Dipartimento di Geoscienze [Padova], INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), Space Science Institute [Macau] (SSI), Macau University of Science and Technology (MUST), 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 für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig [Braunschweig], European Space Astronomy Centre (ESAC), Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), PLANETO - 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), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), California Institute of Technology (CALTECH)-NASA, Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], German Centre for Air and Space Travel, Centre National D'Etudes Spatiales (France), Agenzia Spaziale Italiana, Agencia Estatal de Investigación (España), European Space Agency, Swedish National Space Agency, Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Università degli Studi di Padova = University of Padua (Unipd), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Agence Spatiale Européenne = European Space Agency (ESA), Università degli Studi di Padova = University of Padua (Unipd)-Università degli Studi di Padova = University of Padua (Unipd), 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), ANR-17-CE31-0004,CLASSY,Composition des surfaces du Système Solaire de bas albédo(2017), ITA, USA, GBR, FRA, and DEU
Subjects: 67P/Churyumov-Gerasimenko, Asteroiden und Kometen, photometry, 010504 meteorology & atmospheric sciences, Comet, observational [methods], Data analysis, Narrow angle, High resolution, Individual, rosetta mission, Equinox, Photometric, imaging spectroscopy, Fault scarp, 01 natural sciences, photometric [techniques], techniques: photometric, individual: 67P/Churyumov-Gerasimenko [Comets], 0103 physical sciences, data analysis [methods], Methods, comets, Observational, 010303 astronomy & astrophysics, Southern Hemisphere, 0105 earth and related environmental sciences, [PHYS]Physics [physics], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], biology, comets: individual: 67P/Churyumov-Gerasimenko, Astronomy, Astronomy and Astrophysics, imaging spectroscopy [techniques], biology.organism_classification, methods: data analysis, Techniques, techniques: imaging spectroscopy, 13. Climate action, Space and Planetary Science, Radiance, Comets, Imaging spectroscopy, methods: observational, Osiris, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Geology
Abstract: Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited., The southern hemisphere of comet 67P/Churyumov-Gerasimenko (67P) became observable by the Rosetta mission in March 2015, a few months before cometary southern vernal equinox. The Anhur region in the southern part of the comet's larger lobe was found to be highly eroded, enriched in volatiles, and highly active. Aims. We analyze high-resolution images of the Anhur region pre- and post-perihelion acquired by the OSIRIS imaging system on board the Rosetta mission. The Narrow Angle Camera is particularly useful for studying the evolution in Anhur in terms of morphological changes and color variations. Methods. Radiance factor images processed by the OSIRIS pipeline were coregistered, reprojected onto the 3D shape model of the comet, and corrected for the illumination conditions. Results. We find a number of morphological changes in the Anhur region that are related to formation of new scarps; removal of dust coatings; localized resurfacing in some areas, including boulders displacements; and vanishing structures, which implies localized mass loss that we estimate to be higher than 50 million kg. The strongest changes took place in and nearby the Anhur canyon-like structure, where significant dust cover was removed, an entire structure vanished, and many boulders were rearranged. All such changes are potentially associated with one of the most intense outbursts registered by Rosetta during its observations, which occurred one day before perihelion passage. Moreover, in the niche at the foot of a new observed scarp, we also see evidence of water ice exposure that persisted for at least six months. The abundance of water ice, evaluated from a linear mixing model, is relatively high (>20%). Our results confirm that the Anhur region is volatile-rich and probably is the area on 67P with the most pristine exposures near perihelion.© S. Fornasier et al. 2019, OSIRIS was built by a consortium led by the Max-Planck-Institut fur Sonnensystemforschung, Goettingen, Germany, in collaboration with CISAS, University of Padova, Italy, the Laboratoire d'Astrophysique de Marseille, France, the Instituto de Astrofisica de Andalucia, CSIC, Granada, Spain, the Scientific Support Office of the European Space Agency, Noordwijk, The Netherlands, the Instituto Nacional de Tecnica Aeroespacial, Madrid, Spain, the Universidad Politechnica de Madrid, Spain, the Department of Physics and Astronomy of Uppsala University, Sweden, and the Institut fur Datentechnik und Kommunikationsnetze der Technischen Universitat Braunschweig, Germany. The support of the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain (MEC), Sweden (SNSB), and the ESA Technical Directorate is gratefully acknowledged. We thank the Rosetta Science Ground Segment at ESAC, the Rosetta Mission Operations Centre at ESOC and the Rosetta Project at ESTEC for their outstanding work enabling the science return of the Rosetta Mission. SF acknowledges the financial support from the France Agence Nationale de la Recherche (programme Classy, ANR-17-CE31-0004). The authors thank Dr. E. Howell for her comments and suggestions which helped us to improve this article.
Published: 2019
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