Author: "Thomas Widemann" / Topic: 0103 physical sciences - Searchworks@Jio Institute Digital Library Search Results

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32 results on '"Thomas Widemann"'

1. Venus: key to understanding the evolution of terrestrial planets

Author: Thomas Widemann, R. C. Ghail, and Colin Wilson
Subjects: 010504 meteorology & atmospheric sciences, Planetary habitability, biology, Astronomy and Astrophysics, Venus, Mars Exploration Program, biology.organism_classification, 01 natural sciences, Observations and explorations of Venus, Exoplanet, Astrobiology, law.invention, Orbiter, Space and Planetary Science, law, Planet, 0103 physical sciences, Terrestrial planet, 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract: In this paper, originally submitted in answer to ESA’s “Voyage 2050” call to shape the agency’s space science missions in the 2035–2050 timeframe, we emphasize the importance of a Venus exploration programme for the wider goal of understanding the diversity and evolution of habitable planets. Comparing the interior, surface, and atmosphere evolution of Earth, Mars, and Venus is essential to understanding what processes determined habitability of our own planet and Earth-like planets everywhere. This is particularly true in an era where we expect thousands, and then millions, of terrestrial exoplanets to be discovered. Earth and Mars have already dedicated exploration programmes, but our understanding of Venus, particularly of its geology and its history, lags behind. Multiple exploration vehicles will be needed to characterize Venus’ richly varied interior, surface, atmosphere and magnetosphere environments. Between now and 2050 we recommend that ESA launch at least two M-class missions to Venus (in order of priority): a geophysics-focussed orbiter (the currently proposed M5 EnVision orbiter – [1] – or equivalent); and an in situ atmospheric mission (such as the M3 EVE balloon mission – [2]). An in situ and orbital mission could be combined in a single L-class mission, as was argued in responses to the call for L2/L3 themes [3–5]. After these two missions, further priorities include a surface lander demonstrating the high-temperature technologies needed for extended surface missions; and/or a further orbiter with follow-up high-resolution surface radar imaging, and atmospheric and/or ionospheric investigations.
Published: 2021

2. A Wind Study of Venus’s Cloud Top: New Doppler Velocimetry Observations

Author: Ruben Gonçalves, Pedro Machado, Thomas Widemann, José Francisco Ribeiro, and Francisco Brasil
Subjects: Atmospheric Science, spectroscopy, 010504 meteorology & atmospheric sciences, venus, Venus, Zonal and meridional, doppler velocimetry, Environmental Science (miscellaneous), lcsh:QC851-999, 01 natural sciences, Wind speed, Latitude, Atmosphere, symbols.namesake, 0103 physical sciences, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, biology, Cloud top, biology.organism_classification, Geodesy, atmosphere, dynamics, 13. Climate action, Local time, atmosphere, symbols, lcsh:Meteorology. Climatology, Doppler effect, Geology
Abstract: At Venus&rsquo, s cloud top, the circulation is dominated by the superroration, where zonal wind speed peaks at &sim, 100 ms&minus, 1, in the low-to-middle latitudes. The constraining of zonal and meridional circulations is essential to understanding the mechanisms driving the superrotation of Venus&rsquo, s atmosphere, which are still poorly understood. We present new Doppler velocimetry measurements of horizontal wind velocities at Venus&rsquo, s cloud top, around 70 km altitude. These results were based on March 2015 observations at the Canada&ndash, France&ndash, Hawaii Telescope (CFHT, Mauna Kea, Hawaii), using ESPaDOnS. The Doppler velocimetry method used has already successfully provided zonal and meridional results in previous works led by P. Machado and R. Gon&ccedil, alves, proving to be a good reference ground-based technique in the study of the dynamics of Venus&rsquo, s atmosphere. These observations were carried out between 27 and 29 March 2015, using the Echelle SpectroPolarimetric Device for the Observation of Stars (ESPaDOnS) which provides simultaneous visible-near IR spectra from 370 to 1050 nm, with a spectral resolution of 81000 allowing wind field characterization in the scattered Franuhofer solar lines by Venus&rsquo, s cloud top on the dayside. The zonal velocities are consistent with previous results while also showing evidence of spatial variability, along planetocentric latitude and longitude (local-time). The meridional wind circulation presents a notably constant latitudinal structure with null velocities at lower latitudes, below 10∘ N&ndash, S, and peak velocities of &sim, 30 ms&minus, 1, centered around 35∘ N&ndash, S. The uncertainty of the meridional wind results from ground observations is of the same order as the uncertainty of meridional wind retrieved by space-based observations using cloud-tracking, as also shown by previous work led by R. Gon&ccedil, alves and published in 2020. These March 2015 measurements present a unique and valuable contribution to the study of horizontal wind at the cloud top, from a period when Doppler velocimetry was the only available method to do so, since no space mission was orbiting Venus between Venus Express ending in January 2015 and Akatsuki&rsquo, s orbit insertion in December 2015. These results from new observations provide (1) constraints on zonal wind temporal and spatial variability (latitude and local time), (2) constraints on the meridional wind latitudinal profile, (3) additional evidence of zonal and meridional wind stability for the period between 2011 and 2015 (along previous Doppler results) (4) further evidence of the consistency and robustness of our Doppler velocimetry method.
Published: 2020
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3. HDO and SO2 thermal mapping on Venus

Author: Shigeto Watanabe, Thomas K. Greathouse, Yeon Joo Lee, Carver J. Bierson, Xi Zhang, Wencheng D. Shao, Rohini Giles, Bruno Bézard, Hideo Sagawa, Therese Encrenaz, Sébastien Lebonnois, Thierry Fouchet, Thomas Widemann, Emmanuel Marcq, Franck Lefèvre, Sushil K. Atreya, 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), Southwest Research Institute [San Antonio] (SwRI), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Kyoto Sangyo University, STRATO - LATMOS, Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Planetary Science Laboratory [Ann Arbor] (PSL), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Zentrum für Astronomie und Astrophysik [Berlin] (ZAA), Technische Universität Berlin (TU), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Hokkaido Information University, Department of Earth and Planetary Sciences [Santa Cruz], University of California [Santa Cruz] (UCSC), University of California-University of California, and European Project: 606798,EC:FP7:SPA,FP7-SPACE-2013-1,EUROVENUS(2013)
Subjects: Physics, planets and satellites: atmospheres, 010504 meteorology & atmospheric sciences, biology, Correlation coefficient, Terminator (solar), Imaging spectrometer, Astronomy and Astrophysics, Venus, Astrophysics, biology.organism_classification, 01 natural sciences, planets and satellites: terrestrial planets, 13. Climate action, Space and Planetary Science, Local time, 0103 physical sciences, Mixing ratio, Longitude, infrared: planetary systems, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Line (formation)
Abstract: Since January 2012, we have been monitoring the behavior of sulfur dioxide and water on Venus, using the Texas Echelon Cross-Echelle Spectrograph imaging spectrometer at the NASA InfraRed Telescope Facility (IRTF, Mauna Kea Observatory). Here, we present new data recorded in February and April 2019 in the 1345 cm−1(7.4μm) spectral range, where SO2, CO2, and HDO (used as a proxy for H2O) transitions were observed. The cloud top of Venus was probed at an altitude of about 64 km. As in our previous studies, the volume mixing ratio (vmr) of SO2was estimated using the SO2/CO2line depth ratio of weak transitions; the H2O volume mixing ratio was derived from the HDO/CO2line depth ratio, assuming a D/H ratio of 200 times the Vienna standard mean ocean water. As reported in our previous analyses, the SO2mixing ratio shows strong variations with time and also over the disk, showing evidence for the formation of SO2plumes with a lifetime of a few hours; in contrast, the H2O abundance is remarkably uniform over the disk and shows moderate variations as a function of time. We have used the 2019 data in addition to our previous dataset to study the long-term variations of SO2and H2O. The data reveal a long-term anti-correlation with a correlation coefficient of −0.80; this coefficient becomes −0.90 if the analysis is restricted to the 2014–2019 time period. The statistical analysis of the SO2plumes as a function of local time confirms our previous result with a minimum around 10:00 and two maxima near the terminators. The dependence of the SO2vmr with respect to local time shows a higher abundance at the evening terminator with respect to the morning. The dependence of the SO2vmr with respect to longitude exhibits a broad maximum at 120–200° east longitudes, near the region of Aphrodite Terra. However, this trend has not been observed by other measurements and has yet to be confirmed.
Published: 2020

4. A stringent upper limit on the PH3 abundance at the cloud top of Venus

Author: Clara Sousa-Silva, T. Fouchet, Thomas K. Greathouse, Thérèse Encrenaz, Rohini Giles, Bruno Bézard, Thomas Widemann, Emmanuel Marcq, Hideo Sagawa, Jane S. Greaves, 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), Southwest Research Institute [San Antonio] (SwRI), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Kyoto Sangyo University, School of Physics and Astronomy [Cardiff], Cardiff University, Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), European Project: 606798,EC:FP7:SPA,FP7-SPACE-2013-1,EUROVENUS(2013), 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), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Sorbonne Université (SU), 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), and 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)
Subjects: spectroscopy, 010504 meteorology & atmospheric sciences, Infrared, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Planets, Venus, Astrophysics, 01 natural sciences, Mesosphere, Atmosphere, satellites, Planet, 0103 physical sciences, Mixing ratio, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), biology, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], imaging, Astronomy and Astrophysics, biology.organism_classification, Wavelength, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], atmospheres, Millimeter, Astrophysics - Earth and Planetary Astrophysics
Abstract: Following the announcement of the detection of phosphine (PH$_3$) in the cloud deck of Venus at millimeter wavelengths, we have searched for other possible signatures of this molecule in the infrared range. Since 2012, we have been observing Venus in the thermal infrared at various wavelengths to monitor the behavior of SO$_2$ and H$_2$O at the cloud top. We have identified a spectral interval recorded in March 2015 around 950 cm$^{-1}$ where a PH$_3$ transition is present. From the absence of any feature at this frequency, we derive, on the disk-integrated spectrum, a 3-$\sigma$ upper limit of 5 ppbv for the PH$_3$ mixing ratio, assumed to be constant throughout the atmosphere. This limit is 4 times lower than the disk-integrated mixing ratio derived at millimeter wavelengths. Our result brings a strong constraint on the maximum PH$_3$ abundance at the cloud top and in the lower mesosphere of Venus., Comment: Astronomy & Astrophysics, in press
Published: 2020

5. Atmospheric circulation of Venus measured with visible imaging spectroscopy at the THEMIS observatory

Author: François-Xavier Schmider, Thomas Widemann, Arturo López Ariste, Ivan Gonçalves, B. Gelly, Patrick Gaulme, Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Department of Astronomy [Las Cruces], New Mexico State University, New Mexico Institute of Mining and Technology [New Mexico Tech] (NMT), Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Dynamiques patrimoniales et culturelles (DYPAC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), 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), Télescope héliographique pour l'étude du magnétisme et des instabilites solaires (THEMIS), Centre National de la Recherche Scientifique (CNRS), 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), ANR-15-CE31-0014,JOVIAL,Jupiter : Oscillations en Vitesse radiale par ImAgerie multi Longitudes(2015), Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Météo France-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Météo France-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS), LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université de Paris, 5 place Jules Janssen, 92195 Meudon, France, Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), 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), 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), Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS, Lagrange, and Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, Nice, France.
Subjects: Solar System, 010504 meteorology & atmospheric sciences, Atmospheric circulation, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Venus, Zonal and meridional, Astrophysics, 01 natural sciences, Wind speed, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, Planet, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), ComputingMilieux_MISCELLANEOUS, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), biology, Astronomy and Astrophysics, biology.organism_classification, Solar telescope, 13. Climate action, Space and Planetary Science, Meridional flow, [SDU]Sciences of the Universe [physics], Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: Measuring Venus' atmospheric circulation at different altitudes is important for understanding its complex dynamics, in particular the mechanisms driving the super-rotation. Observationally, Doppler imaging spectroscopy is in principle be the most reliable way to measure wind speeds of planetary atmospheres because it directly provides the projected speed of atmospheric particles. However, high-resolution imaging-spectroscopy is challenging, especially in the visible domain, and most of the knowledge about atmospheric dynamics has been obtained with cloud-tracking technique. The objective of the present work is to measure the global properties of Venus' atmospheric dynamics at the altitude of the uppermost clouds, which is probed by reflected solar lines in the visible domain. Our results are based on high-resolution spectroscopic observations with the long slit spectrometer of the solar telescope THEMIS. We present the first instantaneous "radial-velocity snapshot" of any planet of the solar system in the visible domain, i.e., a complete RV map of the planet obtained by stacking data on less than 10% of its rotation period. From this, we measure the properties of the zonal and meridional winds, which we unambiguously detect. We identify a wind circulation pattern that significantly differs from previous knowledge about Venus. The zonal wind displays a "hot spot" structure, featuring about 200 m/s at sunrise and 70 m/s at noon in the equatorial region. Regarding meridional winds, we detect an equator-to-pole meridional flow peaking at 45 m/s at mid latitudes, i.e., which is about twice as large as what was reported so far., Comment: Accepted in A&A, 23 pages, 19 figures, 3 tables
Published: 2019

6. Lower atmosphere and pressure evolution on Pluto from ground-based stellar occultations, 1988–2016

Author: Jean Lecacheux, Michaël Gillon, Jean Manfroid, Josselin Desmars, Robert R. Howell, T. R. Marsh, G. Benedetti-Rossi, J. G. Greenhill, A. Dias-Oliveira, Ilan Manulis, G. Wortmann, K. M. Ivarsen, J.-E. Communal, S. Renner, F. Vachier, L. Tzouganatos, M. Irzyk, P. Machado, M. Harnisch, Lawrence H. Wasserman, J. Broughton, V. Lorenzi, W. H. Allen, W. Beisker, G. Murawsky, A. Magazzu, David Polishook, J. Marques Oliveira, A. R. Gomes-Junior, M. Conti, J. P. Godard, M. Lavayssière, G. Krannich, Lawrence A. Molnar, Federica B. Bianco, S. de Visscher, Leslie A. Young, Maxime Devogele, Marcelo Assafin, Alessandro Marchini, B. Kattentidt, P. Barroy, G. Dangl, A. Eberle, J. B. Haislip, K. M. Hill, Nora Morales, Andrew A. Cole, P. Enskonatus, B. Loader, Emilio Molinari, V. S. Dhillon, O. Klös, M. Ait Moulay Larbi, Bruno Sicardy, Tanguy Bertrand, Richard Querel, K. Walzel, Diane Berard, P. Lindner, J. P. Rivet, Y. Moulane, L. Di Fabrizio, Rene Duffard, D. Vérilhac, G. McKay, Raoul Behrend, Emmanuel Jehin, Fabio Salvaggio, Greg Bolt, Ricardo Gil-Hutton, J. Milner, Martin Jelínek, J. Sérot, D. Vernet, Kosmas Gazeas, F. Signoret, K. L. Bath, A. C. Gilmore, E. Lellouch, D. Herald, A. Selva, D. Lanoiselée, M. Boutet, Ph. Bendjoya, Shai Kaspi, E. Meza, John Talbot, S. P. Littlefair, Alain Maury, Roberto Vieira-Martins, Marc W. Buie, F. Jabet, S. Kerr, A. Román, Thomas Widemann, C. Opitom, R. Zanmar Sanchez, P. B. Graham, E. Frappa, Catherine B. Olkin, H.-J. Bode, H. Eichler, J. De Queiroz, K. Lindner, A. P. LaCluyze, Zouhair Benkhaldoun, D. Gault, Alain Doressoundiram, François Forget, Riccardo Papini, T. Dobosz, B. E. Morgado, J. Rovira, B. Lade, Daniel E. Reichart, O. Faragó, R. Jansen, Luigi Mancini, A. Noschese, Noah Brosch, Felipe Braga-Ribas, A. Daassou, H. Pavlov, A. Carbognani, S. Todd, F. Colas, Y. El Azhari, C. Peterson, V. Tsamis, M. Bretton, J. Hattenbach, F. Ciabattari, Rodrigo Leiva, C. Veillet, A. J. Castro Tirado, Joe Pollock, R. Naves, Pablo Santos-Sanz, D. Hampf, D. Neel, J. L. Ortiz, S. Alonso, L. Abe, P. M. Kilmartin, Julio Camargo, J. M. Ohlert, D. Gloistein, K. Tigani, F. Marchis, M. Dohrmann, Richard G. French, Ronan Cunniffe, T. Janik, Tamás Tordai, E. F. Young, S. Parker, G. Bonnoli, A. Pennell, M. Kretlow, P. Sogorb, Z. Moravec, W. Rothe, C. Perelló, K. Guhl, A. B. Giles, B. Gährken, Françoise Roques, Valentin D. Ivanov, Giuseppe Leto, 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), Observatório do Valongo/UFRJ [Rio de Janeiro], Universidade Federal do Rio de Janeiro (UFRJ), Centre Hospitalier Universitaire de Nîmes (CHU Nîmes), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Ludwig Maximilians University of Munich, Southwest Research Institute [Boulder] (SwRI), Observatorio Nacional [Rio de Janeiro], Universidade Estadual Paulista Júlio de Mesquita Filho = São Paulo State University (UNESP), Observatório Nacional/MCT, Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), UZEI PRAGUE CZE, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), National Institute of Water and Atmospheric Research [Lauder] (NIWA), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Space Sciences, Technologies and Astrophysics Research Institute (STAR), Department of Physics and Astronomy [Boone], Appalachian State University, University of North Carolina System (UNC)-University of North Carolina System (UNC), Département d'Astrophysique (ex SAP) (DAP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Universidad Nacional de San Juan (UNSJ), University of Sheffield [Sheffield], Kuriwa Observatory, Astronomical Association of Queensland (AAQ), Euraster, Observatoire de Dax, Cardiff School of European Studies (CSES), Cardiff University, Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Fundació Privada Observatori Esteve Duran, The Wise Observatory and The Raymond & Beverly Sackler School of Physics and Astronomy, Tel Aviv University [Tel Aviv], Wise Observatory and Department of geophysics and planetary sciences, Université Cadi Ayyad [Marrakech] (UCA), Stockport Observatory, Occultation Section [Wellington], Royal Astronomical Society of New Zealand, Laboratoire Hippolyte Fizeau (FIZEAU), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, 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), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Università degli Studi di Perugia (UNIPG), Institut Pascal (IP), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-SIGMA Clermont (SIGMA Clermont)-Centre National de la Recherche Scientifique (CNRS), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Astronomical Union of Sparta [Sparta], Laboratoire de Physique de la Matière Condensée - UR UPJV 2081 (LPMC), Université de Picardie Jules Verne (UPJV), PEIRENE (PEIRENE), Institut Génomique, Environnement, Immunité, Santé, Thérapeutique (GEIST), Université de Limoges (UNILIM)-Université de Limoges (UNILIM), Obervatoire des Baronnies Provençales (OBP), Observatorio Montcabre, Institut Laue-Langevin (ILL), ILL, ITA, USA, GBR, FRA, DEU, ESP, ARG, AUS, AUT, BEL, BRA, CHL, GRC, ISR, MAR, NZL, POL, PRT, CZE, CHE, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Ludwig-Maximilians University [Munich] (LMU), Université de Genève = University of Geneva (UNIGE), Universidad Nacional de San Juan [Argentine] (UNSJ), University of California (UC)-University of California (UC), Université Nice Sophia Antipolis (1965 - 2019) (UNS), Tel Aviv University (TAU), Università degli Studi di Perugia = University of Perugia (UNIPG), Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil), Ministerio de Economía y Competitividad (España), European Research Council, European Commission, Ministerio de Ciencia, Innovación y Universidades (España), and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Brasil)
Subjects: planets and satellites: physical evolution, 010504 meteorology & atmospheric sciences, Orbital eccentricity, Context (language use), Surface pressure, Atmospheric sciences, 7. Clean energy, 01 natural sciences, planets and satellites: terrestrial planets, Atmosphere, techniques: photometric, Altitude, Settore FIS/05 - Astronomia e Astrofisica, 0103 physical sciences, methods: observational, methods: data analysis, planets and satellites: atmospheres, observational [Methods], data analysis [Methods], 010303 astronomy & astrophysics, physical evolution [Planets and satellites], Optical depth, 0105 earth and related environmental sciences, methods: observational, methods: data analysis, planets and satellites: atmospheres, techniques: photometric, planets and satellites: physical evolution, planets and satellites: terrestrial planets, Astrophysics - Earth and Planetary Astrophysics, photometric [Techniques], Astronomy and Astrophysics, Albedo, Pluto, 13. Climate action, Space and Planetary Science, terrestrial planets [Planets and satellites], atmospheres [Planets and satellites], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Geology, Astrophysics - Earth and Planetary Astrophysics
Abstract: This article is dedicated to the memory of H.-J. Bode, J. G. Greenhill and O. Faragó for their long-standing support and participation to occultation campaigns. The work leading to these results has received funding from the European Research Council under the European Community’s H2020 2014-2020 ERC Grant Agreement n° 669416 “Lucky Star”. E.M. thanks support from Concytec-Fondecyt-PE and GA, FC-UNI for providing support during the 2012 July 18 occultation. B.S. thanks S. Para for partly supporting this research though a donation, J. P. Beaulieu for helping us accessing to the Hobart Observatory facilities and B. Warner, B. L. Gary, C. Erickson, H. Reitsema, L. Albert, P. J. Merritt, T. Hall, W. J. Romanishin, Y. J. Choi for providing data during the 2007 March 18 occultation. M.A. thanks CNPq (Grants 427700/2018-3, 310683/2017-3 and 473002/2013-2) and FAPERJ (Grant E-26/111.488/2013). J.L.O. thanks support from grant AYA2017-89637-R. P.S.S. acknowledges financial support from the European Union’s Horizon 2020 Research and Innovation Programme, under Grant Agreement no 687378, as part of the project “Small Bodies Near and Far” (SBNAF). J.L.O., R.D., P.S.S. and N.M. acknowledge financial support from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award for the Instituto de Astrofísica de Andalucía (SEV-2017-0709). F.B.R. acknowledges CNPq support process 309578/2017-5. G.B.R. thanks support from the grant CAPES-FAPERJ/PAPDRJ (E26/203.173/2016). J.I.B.C. acknowledges CNPq grant 308150/2016-3. R.V.M. thanks the grants: CNPq-304544/2017-5, 401903/2016-8, and Faperj: PAPDRJ-45/2013 and E-26/203.026/2015. B.M. thanks the CAPES/Cofecub-394/2016-05 grant and CAPES/Brazil – Finance Code 001. B.M. and A.R.G.J. were financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) – Finance Code 001. TRAPPIST-North is a project funded by the University of Liège, in collaboration with Cadi Ayyad University of Marrakech (Morocco). TRAPPIST-South is a project funded by the Belgian Fonds (National) de la Recherche Scientifique (F.R.S.-FNRS) under grant FRFC 2.5.594.09.F, with the participation of the Swiss National Science Foundation (FNS/SNSF). VSD, SPL, TRM and ULTRACAM are all supported by the STFC. K.G. acknowledges help from the team of Archenhold-Observatory, Berlin, and A.R. thanks G. Román (Granada) for help during the observation of the 2016 July 19 occultation. A.J.C.T. acknowledges support from the Spanish Ministry Project AYA2015-71718-R (including EU funds). We thank Caisey Harlingten for the repeated use of his 50 cm telescopes in San Pedro de Atacama, Chile. We thank the Italian Telescopio Nazionale Galileo (TNG), operated on the island of La Palma by the Fundación Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias. L.M. acknowledges support from the Italian Minister of Instruction, University and Research (MIUR) through FFABR 2017 fund and support from the University of Rome Tor Vergata through “Mission: Sustainability 2016” fund. The Astronomical Observatory of the Autonomous Region of the Aosta Valley (OAVdA) is managed by the Fondazione Clément Fillietroz-ONLUS, which is supported by the Regional Governmentof the Aosta Valley, the Town Municipality of Nus and the “Unité des Communes valdôtaines Mont-Émilius”. The research was partially funded by a 2016 “Research and Education”s grant from Fondazione CRT. We thank D.P. Hinson for his constructive and detailed comments that helped to improve this article., Context. The tenuous nitrogen (N2) atmosphere on Pluto undergoes strong seasonal effects due to high obliquity and orbital eccentricity, and has recently (July 2015) been observed by the New Horizons spacecraft. Aims. The main goals of this study are (i) to construct a well calibrated record of the seasonal evolution of surface pressure on Pluto and (ii) to constrain the structure of the lower atmosphere using a central flash observed in 2015. Methods. Eleven stellar occultations by Pluto observed between 2002 and 2016 are used to retrieve atmospheric profiles (density, pressure, temperature) between altitude levels of ~5 and ~380 km (i.e. pressures from ~ 10 μbar to 10 nbar). Results. (i) Pressure has suffered a monotonic increase from 1988 to 2016, that is compared to a seasonal volatile transport model, from which tight constraints on a combination of albedo and emissivity of N2 ice are derived. (ii) A central flash observed on 2015 June 29 is consistent with New Horizons REX profiles, provided that (a) large diurnal temperature variations (not expected by current models) occur over Sputnik Planitia; and/or (b) hazes with tangential optical depth of ~0.3 are present at 4–7 km altitude levels; and/or (c) the nominal REX density values are overestimated by an implausibly large factor of ~20%; and/or (d) higher terrains block part of the flash in the Charon facing hemisphere., European Research Council under the European Community’s H2020 2014-2020 ERC Grant Agreement n° 669416 “Lucky Star”, Grants 427700/2018-3, 310683/2017-3 and 473002/2013-2) and FAPERJ (Grant E-26/111.488/2013), Grant AYA2017-89637-R. P.S.S. acknowledges financial support from the European Union’s Horizon 2020 Research and Innovation Programme, under Grant Agreement no 687378, as part of the project “Small Bodies Near and Far” (SBNAF), Financial support from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award for the Instituto de Astrofísica de Andalucía (SEV-2017-0709), Support process 309578/2017-5. G.B.R. thanks support from the grant CAPES-FAPERJ/PAPDRJ (E26/203.173/2016). J.I.B.C. acknowledges CNPq grant 308150/2016-3. R.V.M. thanks the grants: CNPq-304544/2017-5, 401903/2016-8, and Faperj: PAPDRJ-45/2013 and E-26/203.026/2015. B.M. thanks the CAPES/Cofecub-394/2016-05 grant and CAPES/Brazil – Finance Code 001., Grant FRFC 2.5.594.09.F, with the participation of the Swiss National Science Foundation (FNS/SNSF), Support from the Spanish Ministry Project AYA2015-71718-R (including EU funds), Support from the Italian Minister of Instruction, University and Research (MIUR) through FFABR 2017 fund and support from the University of Rome Tor Vergata through “Mission: Sustainability 2016” fund
Published: 2019

7. HDO and SO2 thermal mapping on Venus. IV. Statistical analysis of the SO2 plumes

Author: Emmanuel Marcq, T. Encrenaz, Franck Lefèvre, T. Fouchet, Yeon Joo Lee, Shigeto Watanabe, Hideo Sagawa, Thomas Widemann, Rohini Giles, Sushil K. Atreya, Thomas K. Greathouse, B. Bézard, Sébastien Lebonnois, 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), Southwest Research Institute [San Antonio] (SwRI), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Kyoto Sangyo University, Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Planetary Science Laboratory [Ann Arbor] (PSL), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, University of Tokyo [Kashiwa Campus], Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Hokkaido Information University, 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), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), 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, and École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris)
Subjects: Physics, planets and satellites: atmospheres, [PHYS]Physics [physics], Vienna Standard Mean Ocean Water, 010504 meteorology & atmospheric sciences, biology, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Equator, Imaging spectrometer, Astronomy and Astrophysics, Venus, Astrophysics, Noon, biology.organism_classification, 01 natural sciences, planets and satellites: terrestrial planets, 13. Climate action, Space and Planetary Science, Local time, 0103 physical sciences, Mixing ratio, Longitude, infrared: planetary systems, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: Since January 2012 we have been monitoring the behavior of sulfur dioxide and water on Venus, using the Texas Echelon Cross-Echelle Spectrograph (TEXES) imaging spectrometer at the NASA InfraRed Telescope Facility (IRTF, Mauna Kea Observatory). We present here the observations obtained between January 2016 and September 2018. As in the case of our previous runs, data were recorded around 1345 cm−1 (7.4 μm). The molecules SO2, CO2, and HDO (used as a proxy for H2O) were observed, and the cloudtop of Venus was probed at an altitude of about 64 km. The volume mixing ratio of SO2 was estimated using the SO2/CO2 line depth ratios of weak transitions; the H2O volume mixing ratio was derived from the HDO/CO2 line depth ratio, assuming a D/H ratio of 200 times the Vienna Standard Mean Ocean Water (VSMOW). As reported in our previous analyses, the SO2 mixing ratio shows strong variations with time and also over the disk, showing evidence of the formation of SO2 plumes with a lifetime of a few hours; in contrast, the H2O abundance is remarkably uniform over the disk and shows moderate variations as a function of time. We performed a statistical analysis of the behavior of the SO2 plumes, using all TEXES data between 2012 and 2018. They appear mostly located around the equator. Their distribution as a function of local time seems to show a depletion around noon; we do not have enough data to confirm this feature definitely. The distribution of SO2 plumes as a function of longitude shows no clear feature, apart from a possible depletion around 100E–150E and around 300E–360E. There seems to be a tendency for the H2O volume mixing ratio to decrease after 2016, and for the SO2 mixing ratio to increase after 2014. However, we see no clear anti-correlation between the SO2 and H2O abundances at the cloudtop, neither on the individual maps nor over the long term. Finally, there is a good agreement between the TEXES results and those obtained in the UV range (SPICAV/Venus Express and UVI/Akatsuki) at a slightly higher altitude. This agreement shows that SO2 observations obtained in the thermal infrared can be used to extend the local time coverage of the SO2 measurements obtained in the UV range.
Published: 2019

8. The Venus Emissivity Mapper (VEM): Obtaining global mineralogy of Venus from orbit

Author: Constantine Tsang, Dennis Wendler, Gabriel Guignan, Emmanuel Marcq, Joern Helbert, Judit Jaenchen, Gabriele Arnold, Nils Mueller, Darby Dyar, Anko Boerner, Mario D'Amore, Suzanne E. Smrekar, Ingo Walter, Alessandro Maturilli, David Kappel, Sabrina Ferrari, Thomas Widemann, DLR Institute of Planetary Research, German Aerospace Center (DLR), Mount Holyoke College, DLR Institute for Optical Sensorsystems, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), DLR Institut für Planetenforschung, 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), 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), 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), Università di Pavia, Southwest Research Institute [Boulder] (SwRI), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Marija Strojnik, Maureen S. Kirk (eds.), 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), 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), Università degli Studi di Pavia, California Institute of Technology (CALTECH)-NASA, Imperial College London, DLR Institute of Optical Sensor Systems, and Università degli Studi di Pavia = University of Pavia (UNIPV)
Subjects: Asteroiden und Kometen, spectroscopy, Weltrauminstrumente, 010504 meteorology & atmospheric sciences, Multispectral image, Venus, 01 natural sciences, law.invention, remote sensing, Planetenphysik, law, 0103 physical sciences, Emissivity, Radar, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Remote sensing, Echtzeit-Datenprozessierung, Venus Emissivity Mapper, biology, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Near-infrared spectroscopy, Leitungsbereich PF, Global Map, biology.organism_classification, Planetary science, 13. Climate action, composition, Orbit (dynamics), Environmental science, Planetare Sensorsysteme
Abstract: The Venus Emissivity Mapper is the first flight instrument designed to focus on mapping the surface of Venus using atmospheric windows around 1 micron. After several years of development, VEM has a mature design with an existing laboratory prototype verifying an achievable instrument SNR of well above 1000, as well as predicted error in retrieval of relative emissivity of better than 1%, assuming the availability of an improved Venus topography. It will provide a global map of rock type, iron contents and redox state of the surface by observing the surface with six narrow band filters, ranging from 0.86 to 1.18 micron. Three additional windows allow corrections for cloud composition and variability, two measure water abundance, and three compensate for stray light. Continuous observation of Venus' thermal emission will also place tighter constraints on current day volcanic activity. Eight of the channels provide measurements of atmospheric water vapor abundance as well as cloud microphysics and dynamics and permit accurate correction of atmospheric interference on the surface data. Combining VEM with a high-resolution radar mapper, such as on the ESA EnVision or NASA VERITAS mission proposals, will provide key insights into the divergent evolution of Venus and Earth.
Published: 2018

9. Search for horizontal and vertical variations of CO in the day and night side lower mesosphere of Venus from CSHELL/IRTF 4.53μm observations

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

10. The Venus Emissivity Mapper concept

Author: Alessandro Maturilli, M. Darby Dyar, Gabriel Guignan, Nils Mueller, Mario D'Amore, Anko Boerner, Jörn Helbert, David Kappel, Thomas Widemann, Emmanuel Marcq, Judit Jaenchen, Suzanne E. Smrekar, Dennis Wendler, Gabriele Arnold, Sabrina Ferrari, Ingo Walter, Strojnik, Marija, Kirk, Maureen, DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), DLR Institute for Optical Sensorsystems, 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), 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), Università degli Studi di Pavia, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Department of Astronomy of the Mount Holyoke College, Mount Holyoke College, Marija Strojnik, Maureen S. Kirk (eds.), DLR Institute of Optical Sensor Systems, and Università degli Studi di Pavia = University of Pavia (UNIPV)
Subjects: Asteroiden und Kometen, spectroscopy, 010504 meteorology & atmospheric sciences, near infrared, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Venus, 01 natural sciences, law.invention, Hochgeschwindigkeitselektronik, Interference (communication), law, 0103 physical sciences, Emissivity, Circular orbit, Radar, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Remote sensing, Echtzeit-Datenprozessierung, geography, geography.geographical_feature_category, biology, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Leitungsbereich PF, Global Map, biology.organism_classification, Volcano, 13. Climate action, Planetare Sensorsysteme, Flight instruments
Abstract: International audience; The Venus Emissivity Mapper (VEM) is the first flight instrument specially designed with a sole focus on mapping the surface of Venus using the narrow atmospheric windows around 1μm. VEM will provide a global map of surface composition as well as redox state of the surface, providing a comprehensive picture of surface-atmosphere interaction on Venus. In addition, continuous observation of the thermal emission of the Venus will provide tight constraints on current day volcanic activity. These capabilities are complemented by measurements of atmospheric water vapor abundance as well as cloud microphysics and dynamic. Atmospheric data will allow for the accurate correction of atmospheric interference on the surface measurements and represent highly valuable science on their own. A mission combining VEM with a high-resolution radar mapper such as the NASA VOX or the ESA EnVision mission proposals in a low circular orbit will provide key insights in the divergent evolution of Venus.
Published: 2017

11. Venus cloud-tracked and doppler velocimetry winds from CFHT/ESPaDOnS and Venus Express/VIRTIS in April 2014

Author: P. Machado, Thomas Widemann, D. Luz, Jean-François Donati, Ruben Gonçalves, Javier Peralta, Department of Genetics [Cambridge], University of Cambridge [UK] (CAM), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency [Sagamihara] (JAXA), 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), 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: Atmospheres, 010504 meteorology & atmospheric sciences, Meteorology, Terminator (solar), Venus, 01 natural sciences, Atmosphere, symbols.namesake, Phase angle (astronomy), Planet, 0103 physical sciences, 010303 astronomy & astrophysics, Spectroscopy, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, [PHYS]Physics [physics], biology, Astronomy and Astrophysics, biology.organism_classification, Geodesy, Dynamics, Space and Planetary Science, Local time, Zonal flow, symbols, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Doppler effect, Geology
Abstract: Accepted: 2016-12-10, 資料番号: SA1160314000
Published: 2017

12. Mapping the thermal structure and minor species of Venus mesosphere with ALMA submillimeter observations

Author: Emmanuel Lellouch, Thierry Fouchet, Arianna Piccialli, Thomas Widemann, R. Moreno, Thérèse Encrenaz, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, [PHYS]Physics [physics], 010504 meteorology & atmospheric sciences, biology, Astronomy and Astrophysics, Context (language use), Venus, Astrophysics, Atacama Large Millimeter Array, Atmospheric sciences, biology.organism_classification, 01 natural sciences, Latitude, Mesosphere, Altitude, 13. Climate action, Space and Planetary Science, Abundance (ecology), [SDU]Sciences of the Universe [physics], 0103 physical sciences, Mixing ratio, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: Context. Water vapor and sulfur compounds are key species in the photochemistry of Venus mesosphere. These species, together with mesospheric temperatures, exhibit drastic temporal variations, both on short timescales (diurnal and day-to-day) as well on long timescales, far from being understood. Aims. We targeted CO, SO, HDO and SO 2 transitions in the submillimeter range using the Atacama Large Millimeter Array (ALMA) to study their spatial and temporal variations. Methods. Four sets of observations were acquired on different dates in November 2011 during the first ALMA Early Science observation Cycle 0. Venus angular diameter was about 11′′ with an illumination factor of 92%, so that mostly the day side of the planet was mapped. Assuming a nominal CO abundance profile, we retrieved vertical temperature profiles over the entire disk as a function of latitude and local time. Temperature profiles were later used to retrieve SO, SO 2 , and H 2 O. We used HDO as a tracer for water assuming a D/H enrichment of 200 times the terrestrial value. Results. We derived 3D maps of mesospheric temperatures in the altitude range 70−105 km. SO, SO 2 , and H 2 O are characterized by a negligible abundance below ~ 85 km followed by an increase with altitude in the upper mesosphere. Disk-averaged SO abundances present a maximum mixing ratio of 15.0 ± 3.1 ppb on November 26 followed the next day by a minimum value of 9.9 ± 1.2 ppb. Due to a very low S/N, SO 2 could only be derived from the disk-averaged spectrum on the first day of observation revealing an abundance of 16.5 ± 4.6 ppb. We found a SO 2 /SO ratio of 1.5 ± 0.4. Global maps of SO reveal strong variations both with latitude and local time and from day to day with abundance ranging from 2 O disk-averages retrievals reveal a steady decrease from November 14 to 27, with the abundance varying from 3.6 ± 0.6 ppm on the first day to 2.9 ± 0.7 ppm on the last day. H 2 O maps reveal a slightly higher abundance on the evening side compared to the morning side and a strong depletion between the first and the second day of observation.
Published: 2017

13. HDO and SO 2 thermal mapping on Venus. III. Short-term and long-term variations between 2012 and 2016

Author: C. DeWitt, Thomas Widemann, Matthew J. Richter, Bruno Bézard, S. K. Atreya, Hideo Sagawa, T. Fouchet, Thomas K. Greathouse, Th. Encrenaz, 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), Southwest Research Institute [San Antonio] (SwRI), University of California [Davis] (UC Davis), University of California, Dynamiques patrimoniales et culturelles (DYPAC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Kyoto Sangyo University, and University of California (UC)
Subjects: 010504 meteorology & atmospheric sciences, Infrared telescope, Imaging spectrometer, Venus, Astrophysics, Rotation, 01 natural sciences, planets and satellites: terrestrial planets, Altitude, 0103 physical sciences, Mixing ratio, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Line (formation), Physics, planets and satellites: atmospheres, biology, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], planets and satellites: composition, Astronomy, Astronomy and Astrophysics, biology.organism_classification, Deuterium, 13. Climate action, Space and Planetary Science, techniques: imaging spectroscopy, [SDU]Sciences of the Universe [physics]
Abstract: International audience; We present the analysis of a four-year observational campaign using the TEXES high-resolution imaging spectrometer at the NASA Infrared Telescope Facility to map sulfur dioxide and deuterated water over the disk of Venus. Data have been recorded in two spectral ranges around 1345 cm −1 (7.4 µm) and 530 cm −1 (19 µm) in order to probe the cloudtop at an altitude of about 64 km (SO 2 and HDO at 7.4 µm) and a few kilometers below (SO 2 at 19 µm). Observations took place during six runs between January 2012 and January 2016. The diameter of Venus ranged between 12 and 33 arcsec. Data were recorded with a spectral resolving power up to 80 000 and a spatial resolution of about 1 arcsec (at 7.4 µm) and 2.5 arcsec (at 19 µm). Mixing ratios were estimated from HDO/CO 2 and SO 2 /CO 2 line depth ratios, using weak neighboring transitions of comparable depths. The whole dataset demonstrates that the two molecules behave very differently to each other. The HDO maps are uniform over the disk. The disk-integrated H 2 O mixing ratio (estimated assuming a D/H of 200 VSMOW in the mesosphere of Venus) show moderate variations (by less than a factor of 2) over the four-year period. A value of 1.0−1.5 ppmv is obtained in most of the cases. The SO 2 maps, in contrast, show strong variations over the disk of Venus, by a factor as high as 5. Long-term variations of SO 2 show that the disk-integrated SO 2 mixing ratio also varies between 2012 and 2016 by a factor as high as ten, with a minimum value of 30 +/−5 ppbv on February 26, 2014 an a maximum value of 300 +/−50 ppbv on January 14, 2016. The SO 2 maps also show a strong short-term variability. It can be seen that the SO 2 maximum feature usually follows the four-day rotation of the clouds over a timescale of two hours, which corresponds to a rotation of 7.5 deg over the planetary disk, but its morphology also changes, which suggests that the lifetime of this structure is not more than a few hours.
Published: 2016

14. Albedo and atmospheric constraints of dwarf planet Makemake from a stellar occultation

Author: S. Roland, J. P. Colque, C. Colazo, Rodolfo Smiljanic, I. de la Cueva, H. J. F. Lima, Jose Luis Ortiz, Javier Licandro, Ricardo Gil-Hutton, Alain Maury, Thomas Widemann, J. Lecacheux, Nicolás Morales, R. Vieira-Martins, Sebastian Bruzzone, T. R. Marsh, Gonzalo Tancredi, D. Weaver, Pablo Santos-Sanz, François Colas, Jean Manfroid, A. Milone, E. Pimentel, Noemi Pinilla-Alonso, Marcelo Assafin, Alexandre S. Oliveira, F. Roques, Valentin D. Ivanov, Daniel Hestroffer, M. Ortiz, D. N. da Silva Neto, V. S. Dhillon, Michaël Gillon, C. Harlingten, Breno L. Giacchini, T. G. Mueller, P. J. Gutiérrez, R. Salvo, Bruno Sicardy, Julio Camargo, Eduardo Unda-Sanzana, Audrey Thirouin, Alvaro Alvarez-Candal, Felipe Braga-Ribas, P. Cacella, M.L. Alonso, A. Campo Bagatin, Leandro Kerber, F. Organero, Marcelo Emilio, Emmanuel Jehin, Rene Duffard, S. P. Littlefair, Raoul Behrend, Emmanuel Lellouch, C. Jacques, 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), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], Physics, Solar System, Multidisciplinary, biology, 010308 nuclear & particles physics, Dwarf planet, Astronomy, Albedo, biology.organism_classification, 01 natural sciences, Occultation, Pluto, Minor-planet moon, 13. Climate action, Geometric albedo, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Eris
Abstract: The icy dwarf planet Makemake has projected axes of 1,430 ± 9 and 1,502 ± 45 km and a V-band geometric albedo larger than Pluto’s but smaller than Eris’s, with no global Pluto-like atmosphere. Makemake is thought to be the third-largest dwarf planet in our Solar System, a little smaller than Pluto and Eris, but until now knowledge of its size and albedo were only approximate. This paper reports the results of observations of the occultation of a faint star known as NOMAD 1181-0235723 by Makemake on 23 April 2011. The data confirm that Makemake is smaller than Pluto and Eris, with axes of 1,430±9 km and 1,502±45 km. Makemake's mean geometric albedo — the ratio of light reflected to light received — is intermediate between that of Pluto and that of Eris. All three are icy, making them among the most reflective objects in the Solar System. And the occultation light curves rule out the presence of a global Pluto-like atmosphere on Makemake, although the presence of dark terrain might imply the presence of a localized atmosphere. Pluto and Eris are icy dwarf planets with nearly identical sizes, comparable densities and similar surface compositions as revealed by spectroscopic studies1,2. Pluto possesses an atmosphere whereas Eris does not; the difference probably arises from their differing distances from the Sun, and explains their different albedos3. Makemake is another icy dwarf planet with a spectrum similar to Eris and Pluto4, and is currently at a distance to the Sun intermediate between the two. Although Makemake’s size (1,420 ± 60 km) and albedo are roughly known5,6, there has been no constraint on its density and there were expectations that it could have a Pluto-like atmosphere4,7,8. Here we report the results from a stellar occultation by Makemake on 2011 April 23. Our preferred solution that fits the occultation chords corresponds to a body with projected axes of 1,430 ± 9 km (1σ) and 1,502 ± 45 km, implying a V-band geometric albedo pV = 0.77 ± 0.03. This albedo is larger than that of Pluto, but smaller than that of Eris. The disappearances and reappearances of the star were abrupt, showing that Makemake has no global Pluto-like atmosphere at an upper limit of 4–12 nanobar (1σ) for the surface pressure, although a localized atmosphere is possible. A density of 1.7 ± 0.3 g cm−3 is inferred from the data.
Published: 2012

15. A ring system detected around the Centaur (10199) Chariklo

Author: K. M. Ivarsen, Kasper Harpsøe, Fernando Roig, N. Ligier, N. R. Frank, Rafael Sfair, Shenghong Gu, Jose Luis Ortiz, J. Lecacheux, Cyrielle Opitom, Jesper Skottfelt, J. B. Haislip, Joe Pollock, Nicolás Morales, L. Vanzi, Rodrigo Leiva, P. Lemos, François Colas, Gonzalo Tancredi, E. M. Schneiter, Frédéric Vachier, Xuefeng Wang, Marcelo Assafin, R. Vieira-Martins, R. G. Sandness, Colin Snodgrass, Nicolás Marín Martínez, Emmanuel Jehin, Marcelo Emilio, Jean Manfroid, L. Almenares, J. Spagnotto, Daniel E. Reichart, S. Roland, Martin Dominik, Thomas Widemann, U. G. Jørgensen, J. P. Moore, V. Perez, A. Ramos Gomes, C. Colazo, Markus Rabus, Pierre Kervella, D. I. Machado, Ricardo Gil-Hutton, L. Mehret, F. Roques, Julio Camargo, Bruno Sicardy, E. Lellouch, D. G. Lambas, G. Benedetti-Rossi, Alain Maury, L. Maquet, M. El Moutamid, A. Ceretta, Rene Duffard, R. Melia, Hektor Monteiro, Aaron P. LaCluyze, Michaël Gillon, F. Char, L. Lorenzini, Felipe Braga-Ribas, 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), Cátedra de Tecnología de la Madera. Departamento de Ingeniería Forestal (CTM-ETSIM), Universidad Politécnica de Madrid (UPM), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Observatorio Nacional [Rio de Janeiro], Observatório do Valongo/UFRJ [Rio de Janeiro], Universidade Federal do Rio de Janeiro (UFRJ), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Space Sciences, Technologies and Astrophysics Research Institute (STAR), Université de Liège, Department of Physics and Astronomy [Boone], Appalachian State University, University of North Carolina System (UNC)-University of North Carolina System (UNC), Southwest Research Institute [Boulder] (SwRI), Universidade Estadual de Ponta Grossa, Universidade Estadual de Ponta Grossa - State University of Ponta Grossa (UEPG), Observatorio Astronómico de Córdoba (OAC), Universidad Nacional de Córdoba [Argentina], Interactions et dynamique des environnements de surface (IDES), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatório do Valongo, Universidade Federal do Rio de Janeiro Ladeira do Pedro Antônio, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), San Pedro de Atacama Celestial Explorations (SPACE), San Pedro de Atacama Celestial Explorations, Universidad Nacional de San Juan [Argentine] (UNSJ), Instituto de Astrofisica de Canarias (IAC), Institut d'Astrophysique et de Géophysique [Liège], Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Max-Planck-Institut für Sonnensystemforschung (MPS), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Universidad Nacional de San Juan (UNSJ), The Royal Society, Science & Technology Facilities Council, and University of St Andrews. School of Physics and Astronomy
Subjects: RING, Solar System, 010504 meteorology & atmospheric sciences, Ciencias Físicas, Haumea, FOS: Physical sciences, Astrophysics, 01 natural sciences, 7. Clean energy, Planet, 0103 physical sciences, QB Astronomy, Trans-Neptunian object, 010303 astronomy & astrophysics, R2C, Astrophysics::Galaxy Astrophysics, ComputingMilieux_MISCELLANEOUS, QB, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Physics, [PHYS]Physics [physics], Debris disk, Multidisciplinary, ~DC~, Astronomy, Radius, Planetary system, Galaxy, Astronomía, Astrophysics::Earth and Planetary Astrophysics, SATELLITES, BDC, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], SYSTEM, CIENCIAS NATURALES Y EXACTAS, Astrophysics - Earth and Planetary Astrophysics
Abstract: Hitherto, rings have been found exclusively around the four giant planets in the Solar System. Rings are natural laboratories in which to study dynamical processes analogous to those that take place during the formation of planetary systems and galaxies. Their presence also tells us about the origin and evolution of the body they encircle. Here we report observations of a multichord stellar occultation that revealed the presence of a ring system around (10199) Chariklo, which is a Centaur-that is, one of a class of small objects orbiting primarily between Jupiter and Neptune-with an equivalent radius of 124â â 9â kilometres (ref. 2). There are two dense rings, with respective widths of about 7 and 3 kilometres, optical depths of 0.4 and 0.06, and orbital radii of 391 and 405 kilometres. The present orientation of the ring is consistent with an edge-on geometry in 2008, which provides a simple explanation for the dimming of the Chariklo system between 1997 and 2008, and for the gradual disappearance of ice and other absorption features in its spectrum over the same period. This implies that the rings are partly composed of water ice. They may be the remnants of a debris disk, possibly confined by embedded, kilometre-sized satellites. © 2014 Macmillan Publishers Limited. Fil: Braga Ribas, F.. Observatório Nacional; Brasil Fil: Sicardy, B.. Universite Pierre et Marie Curie; Francia Fil: Ortiz, J.L.. Consejo Superior de Investigaciones Científicas; España Fil: Snodgrass, C.. Max Planck Institute for Solar System Research; Alemania Fil: Roques, F.. Universite Pierre et Marie Curie; Francia Fil: Vieira Martins, R.. Centre National de la Recherche Scientifique; Francia. Universidade Federal do Rio de Janeiro; Brasil Fil: Camargo, J.I.B.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil Fil: Assafin, M.. Universidade Federal do Rio de Janeiro; Brasil Fil: Duffard, R.. Consejo Superior de Investigaciones Científicas; España Fil: Jehin, E.. Université de Liège; Bélgica Fil: Pollock, J.. Appalachian State University; Estados Unidos Fil: Leiva, R.. Pontificia Universidad Católica de Chile; Chile. Universidad Católica de Chile; Chile Fil: Emilio, M.. Universidade Estadual de Ponta Grossa; Brasil Fil: MacHado, D.I.. Universidade Estadual Do Oeste Do Pará; Brasil Fil: Colazo, C.. Universidad Nacional de Córdoba; Argentina. Ministerio de Educación de la Provincia de Córdoba; Argentina Fil: Lellouch, E.. Universite Pierre et Marie Curie; Francia Fil: Skottfelt, J.. University of Copenhagen; Dinamarca. Geological Museum; Dinamarca Fil: Gillon, M.. Université de Liège; Bélgica Fil: Ligier, N.. Universite Pierre et Marie Curie; Francia Fil: Maquet, L.. Universite Pierre et Marie Curie; Francia Fil: Benedetti Rossi, G.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil Fil: Gomes, A. Ramos. Universidade Federal do Rio de Janeiro; Brasil Fil: Kervella, P.. Universite Pierre et Marie Curie; Francia Fil: Monteiro, H.. Instituto de Física e Química; Brasil Fil: Sfair, R.. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil Fil: Moutamid, M. El. Universite Pierre et Marie Curie; Francia. Centre National de la Recherche Scientifique; Francia Fil: Tancredi, G.. Observatorio Astronómico Los Molinos; Uruguay. Universidad de la República; Uruguay Fil: Spagnotto, J.. Observatorio El Catalejo la Pampa; Argentina Fil: Maury, A.. San Pedro de Atacama Celestial Explorations; Chile Fil: Morales, N.. Consejo Superior de Investigaciones Científicas; España Fil: Gil Hutton, Ricardo Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico ; Argentina Fil: Roland, S.. Observatorio Astronómico Los Molinos; Uruguay Fil: Ceretta, A.. Universidad de la República; Uruguay. Observatorio del IPA; Uruguay Fil: Gu, S.-H.. Chinese Academy of Sciences; República de China Fil: Wang, X.-B.. Chinese Academy of Sciences; República de China Fil: Harpsøe, K.. University of Copenhagen; Dinamarca. Geological Museum; Dinamarca Fil: Rabus, M.. Universidad Católica de Chile; Chile. Pontificia Universidad Católica de Chile; Chile. Max Planck Institute for Astronomy; Alemania Fil: Manfroid, J.. Université de Liège; Bélgica Fil: Opitom, C.. Université de Liège; Bélgica Fil: Vanzi, L.. Pontificia Universidad Católica de Chile; Chile. Universidad Católica de Chile; Chile Fil: Mehret, L.. Universidade Estadual de Ponta Grossa; Fil: Lorenzini, L.. Polo Astronômico Casimiro Montenegro Filho; Brasil Fil: Schneiter, E.M.. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Iate-conicet; Argentina Fil: Melia, R.. Universidad Nacional de Córdoba; Argentina Fil: Lecacheux, J.. Universite Pierre et Marie Curie; Francia Fil: Colas, F.. Centre National de la Recherche Scientifique; Francia Fil: Vachier, F.. Centre National de la Recherche Scientifique; Francia Fil: Widemann, T.. Universite Pierre et Marie Curie; Francia Fil: Almenares, L.. Universidad de la República; Uruguay. Observatorio Astronomico Los Molinos; Uruguay Fil: Sandness, R.G.. San Pedro de Atacama Celestial Explorations; Chile Fil: Char, F.. Universidad de Antofagasta; Chile Fil: Perez, V.. Universidad de la República; Uruguay. Observatorio Astronomico Los Molinos; Uruguay Fil: Lemos, P.. Universidad de la República; Uruguay. Observatorio Astronomico Los Molinos; Uruguay Fil: Martinez, N.. Universidad de la República; Uruguay. Observatorio Astronomico Los Molinos; Uruguay Fil: Jørgensen, U.G.. Universidad de Copenhagen; Dinamarca Fil: Dominik, M.. University of St. Andrews; Reino Unido Fil: Roig, F.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil Fil: Reichart, D.E.. University of North Carolina; Estados Unidos Fil: Lacluyze, A.P.. University of North Carolina; Estados Unidos Fil: Haislip, J.B.. University of North Carolina; Estados Unidos Fil: Ivarsen, K.M.. University of North Carolina; Estados Unidos Fil: Moore, J.P.. University of North Carolina; Estados Unidos Fil: Frank, N.R.. University of North Carolina; Estados Unidos Fil: Garcia Lambas, Diego Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentina
Published: 2014

16. Instrumental Methods for Professional and Amateur Collaborations in Planetary Astronomy

Author: A. Leroy, Sylvain Bouley, John H. Rogers, Paolo Tanga, J. Guarro-Flo, Emmanuel Jehin, Gianluca Masi, C. Buil, Ricardo Hueso, H. B. Hammel, M. Vanhuysse, C. Pellier, A. S. Rajpurohit, P. Drossart, David Baratoux, G. S. Orton, Alice Decock, N. Esseiva, Anny Chantal Levasseur-Regourd, J. M. Gómez-Forrellad, C. Rinner, Georg Fischer, F. Meyer, A. Klotz, Jean Lecacheux, M. Ali Dib, T. Boehm, E. Frappa, F. Colas, Alain Maury, Françoise Roques, Philippe Rousselot, Vincent Boudon, J. P. Beaulieu, Alexandre Santerne, Santiago Pérez-Hoyos, Benoit Carry, R. W. Schmude, A. Wesley, B. Tregon, Thomas Widemann, Leigh N. Fletcher, Brigitte Zanda, Agustín Sánchez-Lavega, W. Beisker, M. Delcroix, Bruno Sicardy, F. Kugel, O. Mousis, D. Herald, S. Foglia, J. M. Petit, Jeremie Vaubaillon, L. Maquet, Mirel Birlan, A. Delsanti, L. Buzzi, Jean-Luc Dauvergne, Jean-Pierre Lebreton, Alexis Bouquet, Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Université de Franche-Comté (UFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Escuela Tecnica Superior de Ingenieria Bilbao, Institut d'Astrophysique de Paris (IAP), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Géosciences Paris Sud (GEOPS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Observatoire de Haute-Provence (OHP), Institut Pythéas (OSU PYTHEAS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS), International Occultation Timing Association European Section (IOTA ES), International Occultation Timing Association European Section, Centre National d'Études Spatiales [Toulouse] (CNES), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, Euraster, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Universidad del Pais Vasco / Euskal Herriko Unibertsitatea [Espagne] (UPV/EHU), 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), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), Department of Earth and Planetary Sciences [Piscataway], Rutgers, The State University of New Jersey [New Brunswick] (RU), Rutgers University System (Rutgers)-Rutgers University System (Rutgers), Dynamique terrestre et planétaire (DTP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire Interdisciplinaire Carnot de Bourgogne (LICB), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), Institut du Porc, Société Astronomique de France (SAF), Association AstroQueyras, Canberra Astronomical Society, Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Observatoire Chante-Perdrix, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), European Southern Observatory (ESO), Departamento de Fı'sica Aplicada I, Association des Utilisateurs de Détecteurs Electroniques (AUDE), Association des Utilisateurs de Détecteurs Electroniques, Association T60, Observatoire Midi-Pyrénées, Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Chercheur indépendant, 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 Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut UTINAM (Univers, transport, interfaces, nanostructures, atmosphère et environnement, molécules) (Besançon), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Departamento de Fisica Aplicada [Bilbao], Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA), Institut de recherche en astrophysique et planétologie (IRAP), 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), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Observatoire Castanet, 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), Association of Universities for Research in Astronomy (AURA), 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 de Astrofísica da Universidade do Porto (CAUP), Universidade do Porto = University of Porto, Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interdisciplinaire Carnot de Bourgogne (ICB), Osservatorio Astronomico Schiaparelli, Association Française d'Astronomie - Ciel et Espace (AFA), Association Française d'Astronomie, Département d'astrophysique, Géophysique et Océanographie (AGO), Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] (AOPP), University of Oxford, Astronomical Research Institute [Ashmore], Fundació Privada Observatori Esteve Duran, Astronomical Ring for Access to Spectroscopy (ARAS), International Occultation Timing Association (IOTA), 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), L'Uranoscope de l'Ile de France, Observatoire de Gretz-Armainvilliers, Department of Physics [Roma Tor Vergata], Università degli Studi di Roma Tor Vergata [Roma], San Pedro de Atacama Celestial Explorations (SPACE), San Pedro de Atacama Celestial Explorations, Observatoire Oukaimeden, JUPOS - Database for Object Positions on Jupiter, British Astronomical Association (BAA), Gordon State College, Laboratoire Ondes et Matière d'Aquitaine (LOMA), Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), OverSky, Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules ( UTINAM ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Franche-Comté ( UFC ), Universidad del Pais Vasco / Euskal Herriko Unibertsitatea ( UPV/EHU ), Institut d'Astrophysique de Paris ( IAP ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de Mécanique Céleste et de Calcul des Ephémérides ( IMCCE ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université de Lille-Centre National de la Recherche Scientifique ( CNRS ), Géosciences Paris Sud ( GEOPS ), Université Paris-Sud - Paris 11 ( UP11 ) -Centre National de la Recherche Scientifique ( CNRS ), European Space Astronomy Center ( ESAC ), European Space Agency ( ESA ), Institut de recherche en astrophysique et planétologie ( IRAP ), Université Paul Sabatier - Toulouse 3 ( UPS ) -Observatoire Midi-Pyrénées ( OMP ) -Centre National de la Recherche Scientifique ( CNRS ), Société Astronomique de France ( SAF ), International Occultation Timing Association European Section ( IOTA ES ), Observatoire Midi-Pyrénées ( OMP ), 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 Diderot - Paris 7 ( UPD7 ) -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'Etudes Spatiales ( CNES ) -Centre National de la Recherche Scientifique ( CNRS ), Association of Universities for Research in Astronomy ( AURA ), IMPEC - 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 ), Jet Propulsion Laboratory ( JPL ), NASA-California Institute of Technology ( CALTECH ), Centro de Astrofísica da Universidade do Porto ( CAUP ), Universidade do Porto [Porto], Joseph Louis LAGRANGE ( LAGRANGE ), Université Nice Sophia Antipolis ( UNS ), Université Côte d'Azur ( UCA ) -Université Côte d'Azur ( UCA ) -Observatoire de la Côte d'Azur, Université Côte d'Azur ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Minéralogie et Cosmochimie du Museum (LMCM), UMR 7202 ( LMCM ), Muséum National d'Histoire Naturelle ( MNHN ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Interdisciplinaire Carnot de Bourgogne ( LICB ), Université de Bourgogne ( UB ) -Centre National de la Recherche Scientifique ( CNRS ), Observatoire Midi-Pyrénées and Association T60, Association Française d'Astronomie - Ciel et Espace ( AFA ), Département d'astrophysique, Géophysique et Océanographie ( AGO ), Space Research Institute of Austrian Academy of Sciences ( IWF ), Austrian Academy of Sciences ( OeAW ), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] ( AOPP ), University of Oxford [Oxford], Astronomical Research Institute {Ashmore], Astronomical Ring for Access to Spectroscopy ( ARAS ), Astronomical Ring for Access to Spectroscopy, International Occultation Timing Association ( IOTA ), International Occultation Timing Association, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace ( LPC2E ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université d'Orléans ( UO ) -Centre National de la Recherche Scientifique ( CNRS ), Department of Physics [Roma], San Pedro de Atacama Celestial Explorations ( SPACE ), British Astronomical Association ( BAA ), University System of Georgia ( USG ), Laboratoire Ondes et Matière d'Aquitaine ( LOMA ), Université de Bordeaux ( UB ) -Centre National de la Recherche Scientifique ( CNRS ), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), European Space Agency (ESA), 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), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), 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), Universidade do Porto, Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Engineering, [PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Planetary Astronomy, 01 natural sciences, Imaging, Photometry, Physics::Popular Physics, Planet, 0103 physical sciences, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Spectroscopy, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Professional-amateur collaborations, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, [ SDU.ASTR.IM ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Astronomy and Astrophysics, [ SDU.ASTR.EP ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Data science, Exoplanet, Physics::History of Physics, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Planetary science, [ PHYS.ASTR.EP ] Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Space and Planetary Science, Asteroid, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, [ PHYS.ASTR.IM ] Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Interplanetary spaceflight, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Instrumentation and Methods for Astrophysics, Amateur, Astrophysics - Earth and Planetary Astrophysics
Abstract: Amateur contributions to professional publications have increased exponentially over the last decades in the field of Planetary Astronomy. Here we review the different domains of the field in which collaborations between professional and amateur astronomers are effective and regularly lead to scientific publications. We discuss the instruments, detectors, softwares and methodologies typically used by amateur astronomers to collect the scientific data in the different domains of interest. Amateur contributions to the monitoring of planets and interplanetary matter, characterization of asteroids and comets, as well as the determination of the physical properties of Kuiper Belt Objects and exoplanets are discussed., 123 pages, Accepted for publication in Experimental Astronomy
Published: 2013

17. Mapping zonal winds at Venus’s cloud tops from ground-based Doppler velocimetry

Author: P. Machado, Olivier Witasse, Emmanuel Lellouch, Thomas Widemann, David Luz, 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), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), and Agence Spatiale Européenne = European Space Agency (ESA)
Subjects: 010504 meteorology & atmospheric sciences, Venus, Atmospheric sciences, 01 natural sciences, Latitude, Atmosphere of Venus, Wind profile power law, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics::Atmospheric and Oceanic Physics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Long-slit spectroscopy, [PHYS]Physics [physics], biology, Astronomy and Astrophysics, biology.organism_classification, 13. Climate action, Space and Planetary Science, Local time, Physics::Space Physics, Zonal flow, Astrophysics::Earth and Planetary Astrophysics, Longitude, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Geology
Abstract: The most significant aspect of the general circulation of the atmosphere of Venus is its retrograde super-rotation. A complete characterization of this dynamical phenomenon is crucial for understanding its driving mechanisms. Here we report on ground-based Doppler velocimetry measurements of the zonal winds, based on high resolution spectra from the UV–Visual Echelle Spectrograph (UVES) instrument at ESO’s Very Large Telescope. Under the assumption of predominantly zonal flow, this method allows the simultaneous direct measurement of the zonal velocity across a range of latitudes and local times in the day side. The technique, based on long slit spectroscopy combined with the high spatial resolution provided by the VLT, has provided the first ground-based characterization of the latitudinal profile of zonal wind in the atmosphere of Venus, the first zonal wind field map in the visible, as well as new constraints on wind variations with local time. We measured mean zonal wind amplitudes between 106 ± 21 and 127 ± 14 m/s at latitudes between 18°N and 34°S, with the zonal wind being approximately uniform in 2.6°-wide latitude bands (0.3 arcsec at disk center). The zonal wind profile retrieved is consistent with previous spacecraft measurements based on cloud tracking, but with non-negligible variability in local time (longitude) and in latitude. Near 50° the presence of moderate jets is apparent in both hemispheres, with the southern jet being stronger by ∼10 m/s. Small scale wind variations with local time are also present at low and mid-latitudes.
Published: 2012

18. HDO and SO 2 thermal mapping on Venus: evidence for strong SO 2 variability

Author: Matthew J. Richter, John H. Lacy, Henry G. Roe, Bruno Bézard, Th. Encrenaz, T. Fouchet, Thomas Widemann, Thomas K. Greathouse, 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), Southwest Research Institute [San Antonio] (SwRI), Department of Astronomy [Austin], and University of Texas at Austin [Austin]
Subjects: Physics, [PHYS]Physics [physics], 010504 meteorology & atmospheric sciences, biology, Imaging spectrometer, Astronomy and Astrophysics, Venus, Atmosphere of Mars, Astrophysics, biology.organism_classification, 01 natural sciences, Spectral line, 13. Climate action, Space and Planetary Science, 0103 physical sciences, Mixing ratio, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Mixing (physics), Water vapor, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Line (formation)
Abstract: We have been using the TEXES high-resolution imaging spectrometer at the NASA Infrared Telescope Facility to map sulfur dioxide and deuterated water over the disk of Venus. Observations took place on January 10–12, 2012. The diameter of Venus was 13 arcsec, with an illumination factor of 80%. Data were recorded in the 1344–1370 cm −1 range (around 7.35 μm) with a spectral resolving power of 80 000 and a spatial resolution of about 1.5 arcsec. In this spectral range, the emission of Venus comes from above the cloud top (z = 60–80 km). Four HDO lines and tens of SO2 lines have been identified in our spectra. Mixing ratios have been estimated from HDO/CO2 and SO2/CO2 line depth ratios, using weak neighboring transitions of comparable depths. The HDO maps, recorded on Jan. 10 and Jan. 12, are globally uniform with no significant variation between the two dates. A slight enhancement of the HDO mixing ratio toward the limb might be interpreted as a possible increase of the D/H ratio with height above the cloud level. The mean H2O mixing ratio is found to be 1.5 +/−0.75 ppm, assuming a D/H ratio of 0.0312 (i.e. 200 times the terrestrial value) over the cloud deck. The SO2 maps, recorded each night from Jan. 10 to Jan. 12, show strong variations over the disk of Venus, by a factor as high as 5 to 10. In addition, the position of the maximum SO2 mixing ratio strongly varies on a timescale of 24 h. The maximum SO2 mixing ratio ranges between 75 +/−25 ppb and 125 +/−50 ppb between Jan. 10 and Jan. 12. The high variability of sulfur dioxide is probably a consequence of its very short photochemical lifetime.
Published: 2012

19. Sunlight refraction in the mesosphere of Venus during the transit on June 8th, 2004

Author: Lorenzo Comolli, Thomas Widemann, A. Rondi, S. Rondi, Jay M. Pasachoff, Bruno Sicardy, P. Sütterlin, Paolo Tanga, J. Arnaud, Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, and Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, Physics - History and Philosophy of Physics, FOS: Physical sciences, Venus, 01 natural sciences, Latitude, Photometry (optics), Atmosphere, Atmosphere of Venus, Physics - Geophysics, Planet, 0103 physical sciences, History and Philosophy of Physics (physics.hist-ph), Transit (astronomy), 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), biology, Astronomy, Astronomy and Astrophysics, biology.organism_classification, Refraction, Geophysics (physics.geo-ph), 13. Climate action, Space and Planetary Science, Geology, Astrophysics - Earth and Planetary Astrophysics
Abstract: Many observers in the past gave detailed descriptions of the telescopic aspect of Venus during its extremely rare transits across the Solar disk. In particular, at the ingress and egress, the portion of the planet's disk outside the Solar photosphere has been repeatedly perceived as outlined by a thin, bright arc ("aureole"). Those historical visual observations allowed inferring the existence of Venus' atmosphere, the bright arc being correctly ascribed to the refraction of light by the outer layers of a dense atmosphere. On June 8th, 2004, fast photometry based on electronic imaging devices allowed the first quantitative analysis of the phenomenon. Several observers used a variety of acquisition systems to image the event -- ranging from amateur-sized to professional telescopes and cameras -- thus collecting for the first time a large amount of quantitative information on this atmospheric phenomenon. In this paper, after reviewing some elements brought by the historical records, we give a detailed report of the ground based observations of the 2004 transit. Besides confirming the historical descriptions, we perform the first photometric analysis of the aureole using various acquisition systems. The spatially resolved data provide measurements of the aureole flux as a function of the planetocentric latitude along the limb. A new differential refraction model of solar disk through the upper atmosphere allows us to relate the variable photometry to the latitudinal dependency of scale-height with temperature in the South polar region, as well as the latitudinal variation of the cloud-top layer altitude. We compare our measurements to recent analysis of the Venus Express VIRTIS-M, VMC and SPICAV/SOIR thermal field and aerosol distribution. Our results can be used a starting point for new, more optimized experiments during the 2012 transit event., Comment: Icarus, in press
Published: 2012

20. A Pluto-like radius and a high albedo for the dwarf planet Eris from an occultation

Author: W. J. B. Corradi, G. P. Tozzi, D. N. da Silva Neto, S. Pastor, A. Castro, R. Gil Hutton, Petr Kubánek, P. Santos-Sanz, Felipe Braga-Ribas, L. Cuesta, L. Gutiérrez, E. Lellouch, M. T. Eibe, S. Saravia, R. Vieira Martins, H. Hernández-Toledo, Jean Manfroid, C. Jacques, A. Ramos Gomes, I. de la Cueva, A. Milone, Marcelo Emilio, Juan Fabregat, Stefano Mottola, F. Roques, Martin Jelínek, José M. Madiedo, E. García Melendo, D. Weaver, M. Cebrián, Pilar Montañés-Rodríguez, Audrey Thirouin, A. Ullán, Iain A. Steele, Wilson Reis, Roberto Vázquez, J. Lecacheux, Michaël Gillon, A. J. Castro-Tirado, Marcelo Assafin, Jose Luis Ortiz, Alain Maury, Alfredo Sota, J.A. de los Reyes, C. Harlingten, Bruno Sicardy, Emmanuel Jehin, V. Peris, Alejandro Oscoz, Daniel Hestroffer, G. Muler, R. Sanchez-Ramirez, Nicolás Morales, Alexandre Humberto Andrei, François Colas, Thomas Widemann, F. Organero, Julio Camargo, Fabio P. Santos, S. Pedraz, Rene Duffard, Raoul Behrend, 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), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Observatório do Valongo/UFRJ [Rio de Janeiro], Universidade Federal do Rio de Janeiro (UFRJ), Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, San Pedro de Atacama Celestial Explorations (SPACE), San Pedro de Atacama Celestial Explorations, Complejo Astronómico El Leoncito [San Juan] (CASLEO), Universidad Nacional de Córdoba [Argentina]-Consejo Nacional de Investigaciones Científicas y Técnicas [Buenos Aires] (CONICET)-Universidad Nacional de San Juan (UNSJ)-Universidad Nacional de la Plata [Argentine] (UNLP), Observatório Nacional/MCT, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Observatório do Valongo, Universidade Federal do Rio de Janeiro Ladeira do Pedro Antônio, Universidade Estadual da Zona Oeste (UEZO), Universidade Estadual da Zona Oeste, INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Caisey Harlingten Observatory, Geneva Observatory, University of Geneva [Switzerland], German Aerospace Center (DLR), Fundació Privada Observatori Esteve Duran, Institut de Ciencies de l'Espai [Barcelona] (ICE-CSIC), Observatorio Astronomico de Valencia, Universitat de València (UV), Facultad de Ciencias Experimentales, Universidad de Huelva, Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Observatorio astronómico de La Hita, Observatorio de la Murta, Centro Astronómico Hispano Alemán, Observatorio de Calar Alto (CAHA), Sociedad Malagueña de Astronomía, Centro Cultural José María Gutiérrez Romero, Astroimagen, Observatorio Nazaret, Liverpool JMU, Instituto de Astrofisica de Canarias (IAC), Observatório Astronomico Christus, Colégio Christus, Observatório CEAMIG-REA, Instituto de Ciências Exatas, Departamento de Física, Universidade Federal de Minas Gerais, Instituto Nacional de Pesquisas Espaciais (INPE), Ministério da Ciência, Tecnologia e Inovação, Universidade Estadual de Ponta Grossa, Universidade Estadual de Ponta Grossa - State University of Ponta Grossa (UEPG), Instituto de Astronomía, Universidad Nacional Autónoma de México (UNAM), Universidad Nacional de Córdoba [Argentina]-Consejo Nacional de Investigaciones Científicas y Técnicas [Buenos Aires] (CONICET)-Universidad Nacional de San Juan [Argentine] (UNSJ)-Universidad Nacional de la Plata [Argentine] (UNLP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Université de Genève = University of Geneva (UNIGE), and Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM)
Subjects: 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Ciencias Físicas, Astronomical unit, Dwarf planet, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Orbital eccentricity, Astrophysics, no utilizado, 01 natural sciences, 7. Clean energy, Occultation, dwarf planet, Atmosphere, 0103 physical sciences, Trans-Neptunian object, 010303 astronomy & astrophysics, Eris, 0105 earth and related environmental sciences, Physics, Multidisciplinary, biology, Pluto, Astronomy, biology.organism_classification, Astronomía, 13. Climate action, CIENCIAS NATURALES Y EXACTAS, albedo
Abstract: The dwarf planet Eris is a trans-Neptunian object with an orbital eccentricity of 0.44, an inclination of 44 degrees and a surface composition very similar to that of Pluto. It resides at present at 95.7 astronomical units (1ĝ€‰au is the Earth-Sun distance) from Earth, near its aphelion and more than three times farther than Pluto. Owing to this great distance, measuring its size or detecting a putative atmosphere is difficult. Here we report the observation of a multi-chord stellar occultation by Eris on 6 November 2010 ut. The event is consistent with a spherical shape for Eris, with radius 1,163±6 kilometres, density 2.52±0.05 grams per cm 3 and a high visible geometric albedo,. No nitrogen, argon or methane atmospheres are detected with surface pressure larger than about 10,000 times more tenuous than Pluto's present atmosphere. As Pluto's radius is estimated to be between 1,150 and 1,200 kilometres, Eris appears as a Pluto twin, with a bright surface possibly caused by a collapsed atmosphere, owing to its cold environment. We anticipate that this atmosphere may periodically sublimate as Eris approaches its perihelion, at 37.8 astronomical units from the Sun. © 2011 Macmillan Publishers Limited. All rights reserved. Fil: Sicardy, B.. Universite Pierre et Marie Curie; Francia. Institut Universitaire de France; Francia Fil: Ortiz, J.L.. Consejo Superior de Investigaciones Científicas; España Fil: Assafin, M.. Universidade Federal do Rio de Janeiro; Brasil Fil: Jehin, E.. Université de Liège; Bélgica Fil: Maury, A.. San Pedro de Atacama Celestial Explorations; Chile Fil: Lellouch, E.. Universite Pierre et Marie Curie; Francia Fil: Gil Hutton, Ricardo Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico ; Argentina Fil: Braga Ribas, F.. Universite Pierre et Marie Curie; Francia. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil Fil: Colas, F.. Universite Pierre et Marie Curie; Francia Fil: Hestroffer, D.. Universite Pierre et Marie Curie; Francia Fil: Lecacheux, J.. Universite Pierre et Marie Curie; Francia Fil: Roques, F.. Universite Pierre et Marie Curie; Francia Fil: Santos-Sanz, P.. Universite Pierre et Marie Curie; Francia Fil: Widemann, T.. Universite Pierre et Marie Curie; Francia Fil: Morales, N.. Consejo Superior de Investigaciones Científicas; España Fil: Duffard, R.. Consejo Superior de Investigaciones Científicas; España Fil: Thirouin, A.. Consejo Superior de Investigaciones Científicas; España Fil: Castro-Tirado, A.J.. Consejo Superior de Investigaciones Científicas; España Fil: Jelínek, M.. Consejo Superior de Investigaciones Científicas; España Fil: Kubánek, P.. Consejo Superior de Investigaciones Científicas; España Fil: Sota, A.. Consejo Superior de Investigaciones Científicas; España Fil: Sánchez-Ramírez, R.. Consejo Superior de Investigaciones Científicas; España Fil: Andrei, A.H.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil. Universidade Federal do Rio de Janeiro; Brasil Fil: Camargo, J.I.B.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil. Universidade Federal do Rio de Janeiro; Brasil Fil: Da Silva Neto, D.N.. Centro Universitário Estadual Da Zona Oeste; . Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil Fil: Gomes Jr., A. Ramos. Universidade Federal do Rio de Janeiro; Brasil Fil: Martins, R. Vieira. Universite Pierre et Marie Curie; Francia. Universidade Federal do Rio de Janeiro; Brasil. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil Fil: Gillon, M.. Université de Liège; Bélgica Fil: Manfroid, J.. Université de Liège; Bélgica Fil: Tozzi, G.P.. Osservatorio Astrofisico di Arcetri; Italia Fil: Harlingten, C.. Caisey Harlingten Observatory; Reino Unido Fil: Saravia, S.. San Pedro de Atacama Celestial Explorations; Chile Fil: Behrend, R.. Universidad de Ginebra; Suiza Fil: Mottola, S.. German Aerospace Center; Alemania Fil: Melendo, E. García. Universitat Autònoma de Barcelona; España. Consejo Superior de Investigaciones Científicas; España Fil: Peris, V.. Universidad de Valencia; España Fil: Fabregat, J.. Universidad de Valencia; España Fil: Madiedo, J.M.. Universidad de Huelva; España Fil: Cuesta, L.. Consejo Superior de Investigaciones Científicas; España Fil: Eibe, M.T.. Consejo Superior de Investigaciones Científicas; España Fil: Ullán, A.. Consejo Superior de Investigaciones Científicas; España Fil: Organero, F.. Observatorio astronómico de La Hita; España Fil: Pastor, S.. Observatorio de la Murta; España Fil: De Los Reyes, J.A.. Observatorio de la Murta; España Fil: Pedraz, S.. Centro Astronómico Hispano Alemán; España Fil: Castro, A.. Centro Cultural José María Gutiérrez Romero; España Fil: De La Cueva, I.. Astroimagen; España Fil: Muler, G.. Observatorio Nazaret; España Fil: Steele, I.A.. Liverpool JMU; Reino Unido Fil: Cebrián, M.. Instituto Astrofisico de Canarias; Fil: Montañés-Rodríguez, P.. Instituto Astrofisico de Canarias; España Fil: Oscoz, A.. Instituto Astrofisico de Canarias; España Fil: Weaver, D.. Observatório Astronomico Christus; Brasil Fil: Jacques, C.. Observatório CEAMIG-REA; Brasil Fil: Corradi, W.J.B.. Universidade Federal do Minas Gerais; Brasil Fil: Santos, F.P.. Universidade Federal do Minas Gerais; Brasil Fil: Reis, W.. Universidade Federal do Minas Gerais; Brasil Fil: Milone, A.. Instituto Nacional de Pesquisas Espaciais; Brasil Fil: Emilio, M.. Universidade Estadual de Ponta Grossa; Brasil Fil: Gutiérrez, L.. Universidad Nacional Autónoma de México; México Fil: Vázquez, R.. Universidad Nacional Autónoma de México; México Fil: Hernández Toledo, H.. Universidad Nacional Autónoma de México; México
Published: 2011

21. Transmission spectrum of Venus as a transiting exoplanet

Author: Paolo Tanga, Thomas Widemann, A. Lecavelier des Etangs, Guillaume Gronoff, Jean Lilensten, David Ehrenreich, Alfred Vidal-Madjar, Mathieu Barthelemy, Luc Arnold, Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, and Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Earth and Planetary Astrophysics (astro-ph.EP), biology, 010308 nuclear & particles physics, FOS: Physical sciences, Astronomy and Astrophysics, Venus, Astrophysics, Planetary system, biology.organism_classification, 01 natural sciences, Exoplanet, Astrobiology, Atmosphere, Atmosphere of Venus, 13. Climate action, Space and Planetary Science, Planet, 0103 physical sciences, Transit (astronomy), 010303 astronomy & astrophysics, Circumstellar habitable zone, ComputingMilieux_MISCELLANEOUS, Astrophysics - Earth and Planetary Astrophysics
Abstract: On 5-6 June 2012, Venus will be transiting the Sun for the last time before 2117. This event is an unique opportunity to assess the feasibility of the atmospheric characterisation of Earth-size exoplanets near the habitable zone with the transmission spectroscopy technique and provide an invaluable proxy for the atmosphere of such a planet. In this letter, we provide a theoretical transmission spectrum of the atmosphere of Venus that could be tested with spectroscopic observations during the 2012 transit. This is done using radiative transfer across Venus' atmosphere, with inputs from in-situ missions such as Venus Express and theoretical models. The transmission spectrum covers a range of 0.1-5 {\mu}m and probes the limb between 70 and 150 km in altitude. It is dominated in UV by carbon dioxide absorption producing a broad transit signal of ~20 ppm as seen from Earth, and from 0.2 to 2.7 {\mu}m by Mie extinction (~5 ppm at 0.8 {\mu}m) caused by droplets of sulfuric acid composing an upper haze layer above the main deck of clouds. These features are not expected for a terrestrial exoplanet and could help discriminating an Earth-like habitable world from a cytherean planet., Comment: 4 pages, 3 figures, 1 table. Figure 3 and Table 1 will be only available on-line. Table 1 will be fully available at the CDS. Accepted for publication in Astronomy and Astrophysics (Letter)
Published: 2011
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22. The science of EChO

Author: James Frith, Marina Galand, Emmanuel Lellouch, Antonino La Barbera, M. J. Barlow, Marcell Tessenyi, Peter Doel, Ignasi Ribas, Jesus Maldonado Prado, Sergey N. Yurchenko, David M. Kipping, Pactrick Guio, Roy van Boekel, Peter H. Hauschildt, Remco de Kok, Antonio Maggio, Maria R. Zapatero-Osorio, David Pinfield, Emanuele Pace, Mercedes Lopez Morales, Raman K. Prinja, Géza Kovács, Mark G. Swain, Angioletta Coradini, Richard P. Nelson, Patrick Gaulme, Julianne I. Moses, Ingo Mueller-Wodarg, Jean-Philippe Beaulieu, Alan D. Aylward, Gáspár Á. Bakos, Thomas Widemann, Giovanni Strazzulla, Céline Cavarroc, Manuel Guedel, Caitlin A. Griffith, Olivier Hainaut, S. J. Fossey, Pascal Bordé, Ennio Poretti, Giorgio Savini, Jeroen Bouwman, Jean-Pierre Maillard, Eric Pantin, Mercedes López-Morales, Leen Decin, Miguel A. Lopez Valverde, Olivier Mousis, Peter A. R. Ade, Pieter Deroo, Olivier Demangeon, Kevin Heng, James Y-K. Cho, Angela Ciaravella, Amaya Moro-Martin, Daphne Stam, Tristan Guillot, Bruno Bézard, Franck Selsis, Roger V. Yelle, Lisa Kaltenegger, Pascal Fouqué, Alessandro Sozzetti, Alberto Adriani, Linda R. Brown, Giovanna Tinetti, Loredana Prisinzano, Giuseppina Micela, Thomas Henning, Vincent Coudé du Foresto, Craig B. Agnor, Ulrich Grözinger, Yuk Yung, Michael Meyer, Robert J. Hargreaves, Marc Ollivier, Ansgar Reiners, Ricardo Hueso, Enzo Pascale, Alan Smith, Nicholas Achilleos, Dimitar Sasselov, Robin Wordsworth, Jonathan Tennyson, Bruce Swinyard, Carlos Allende Prieto, Sergio Molinari, Manuel López-Puertas, Peter F. Bernath, David Heyrovsky, Ignas Snellen, Bruno Sicardy, Oliver Krause, Gautam Vasisht, Steve Miller, Christophe Lovi, Matthew James Griffin, Athena Coustenis, Napoléon Nguyen Tuong, Ingo Waldmann, Glenn S. Orton, Giuseppe Leto, B. Samuel, Patrick Kervella, Pierre F. L. Maxted, F. J. Martin-Torres, Lee Grenfell, Patrick G. J. Irwin, Stefano Pezzuto, Cristina Afonso, Olivier Grasset, Thérèse Encrenaz, Jonay I. González Hernández, Helmut Lammer, Davide Grassi, Serena Viti, Enric Palle, Tommi Koskinen, Jorge Sanz Forcada, Glenn J. White, Camilla Danielski, François Forget, Leigh N. Fletcher, Jean-Michel Reess, Arnaud Cassan, J. B. Marquette, Matteo Focardi, D. Montes, R. J. Barber, Sandrine Vinatier, Charles S. Cockell, Lars Stixrude, Pierre Drossart, University College of London [London] (UCL), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, 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), Department of Physics and Astronomy [UCL London], Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Istituto di Fisica dello Spazio Interplanetario (INAF), Consiglio Nazionale delle Ricerche [Roma] (CNR), 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), Département d'Astrophysique (ex SAP) (DAP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1, Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Institut d'Astrophysique de Paris (IAP), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Liquides Ioniques et Interfaces Chargées (LI2C), Université Pierre et Marie Curie - Paris 6 (UPMC)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Palermo (OAPa), Istituto Nazionale di Astrofisica (INAF), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), SRON Netherlands Institute for Space Research (SRON), University of Calgary, Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), School of Physics and Astronomy [London], Queen Mary University of London (QMUL), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Astronomische Rechen-Institut [Heidelberg] (ARI), Zentrum für Astronomie der Universität Heidelberg (ZAH), Universität Heidelberg [Heidelberg]-Universität Heidelberg [Heidelberg], Planetary and Space Sciences Research Institute [Milton Keynes] (PSSRI), Centre for Earth, Planetary, Space and Astronomical Research [Milton Keynes] (CEPSAR), The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] (AOPP), University of Oxford [Oxford], Institut Pierre-Simon-Laplace (IPSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National d'Études Spatiales [Toulouse] (CNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-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), Blackett Laboratory, Imperial College London, Istituto di Fisica dello Spazio Interplanetario (IFSI), Consiglio Nazionale delle Ricerche (CNR), Escuela Superior de Ingenieria, Universidad del Pais Vasco / Euskal Herriko Unibertsitatea [Espagne] (UPV/EHU), Harvard-Smithsonian Center for Astrophysics (CfA), Smithsonian Institution-Harvard University [Cambridge], Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Department of Science and Technology Studies [London] (STS), Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Imperial College Healthcare NHS Trust, STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC), Department of Physics and Astronomy [Milton Keynes], The Open University [Milton Keynes] (OU), Université Nice Sophia Antipolis (1965 - 2019) (UNS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB), 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 Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Universität Heidelberg [Heidelberg] = Heidelberg University-Universität Heidelberg [Heidelberg] = Heidelberg University, University of Oxford, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), 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), Harvard University-Smithsonian Institution, Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie et Géodynamique UMR6112 (LPG), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Université d'Angers (UA), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Centre National de la Recherche Scientifique (CNRS)-ESPCI ParisTech-Université Pierre et Marie Curie - Paris 6 (UPMC), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), California Institute of Technology (CALTECH)-NASA, École normale supérieure - Paris (ENS Paris)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National d'Études Spatiales [Toulouse] (CNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, and Harvard University [Cambridge]-Smithsonian Institution
Subjects: Solar System, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Luchtkwaliteit, 01 natural sciences, 7. Clean energy, Astrobiology, Air Quality, Kepler-47, Planet, formation [Planetary systems], 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, planets and satellites: formation, Kepler-62, 010303 astronomy & astrophysics, planetary systems, Astrophysics::Galaxy Astrophysics, QC, Physics, 010308 nuclear & particles physics, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics, planets and satellites: general, Planetary system, Exoplanet, general [Planets and satellites], planetary systems: formation, Planetary systems, 13. Climate action, Space and Planetary Science, Terrestrial planet, Planetary systems: formation, Planets and satellites: formation, Planets and satellites: general, Astrophysics::Earth and Planetary Astrophysics, Circumstellar habitable zone, formation [Planets and satellites]
Abstract: The science of extra-solar planets is one of the most rapidly changing areas of astrophysics and since 1995 the number of planets known has increased by almost two orders of magnitude. A combination of ground-based surveys and dedicated space missions has resulted in 560-plus planets being detected, and over 1200 that await confirmation. NASA's Kepler mission has opened up the possibility of discovering Earth-like planets in the habitable zone around some of the 100,000 stars it is surveying during its 3 to 4-year lifetime. The new ESA's Gaia mission is expected to discover thousands of new planets around stars within 200 parsecs of the Sun. The key challenge now is moving on from discovery, important though that remains, to characterisation: what are these planets actually like, and why are they as they are?In the past ten years, we have learned how to obtain the first spectra of exoplanets using transit transmission and emission spectroscopy. With the high stability of Spitzer, Hubble, and large ground-based telescopes the spectra of bright close-in massive planets can be obtained and species like water vapour, methane, carbon monoxide and dioxide have been detected. With transit science came the first tangible remote sensing of these planetary bodies and so one can start to extrapolate from what has been learnt from Solar System probes to what one might plan to learn about their faraway siblings. As we learn more about the atmospheres, surfaces and near-surfaces of these remote bodies, we will begin to build up a clearer picture of their construction, history and suitability for life.The Exoplanet Characterisation Observatory, EChO, will be the first dedicated mission to investigate the physics and chemistry of Exoplanetary Atmospheres. By characterising spectroscopically more bodies in different environments we will take detailed planetology out of the Solar System and into the Galaxy as a whole.EChO has now been selected by the European Space Agency to be assessed as one of four M3 mission candidates.
Published: 2010

23. Titania's radius and an upper limit on its atmosphere from the September 8, 2001 stellar occultation

Author: Emmanuel Lellouch, F. Díaz, Ph. Dupouy, P. Figuereido, B. Mitchell, C. Birnbaum, W. Sutherland, H. Mendt, C. Labordena, C. Martinez, P. Valdes Sada, F. Schwartz, P. Burlot, E. van Ballegoij, C. Clarasso-Llauger, J.-F. Coliac, C. Sire, R. Jones, M. Kretlow, P. Maley, S. Rivaud, J. Lecacheux, J.M. Winkel, A. Cidadão, C. Saraiva, R. E. Hill, C. Marlot, S. Pau, F. Colas, F. Roques, E. López, C. Marciano, M. Gabaldá-Sánchez, C. Demeautis, P. Coelho, A. Roca, C. Schnabel, Jean-Eudes Arlot, Pedro Ré, R. Gonçalves, R. Hernández, C. Buil, A.J. Elliott, E. Masana, A. Ardanuy, C. Guillén, J.-F. Lecampion, F. Casarramona, William B. Hubbard, X. Simbaña, L. Rivas, L. Omar Porras, H. Callender, E. Brochard, J. L. Ortiz, M. Rapaport, D. Pulupa, A. Peña, J. Gonçalves, G. Sánchez, G. Rau, A. Hernández, B.M. Ewen-Smith, A. Arnal, Pascal Dubreuil, C. Lambin, C. R. Hills, E. Pallo, K. Daiffallah, X. Otazu-Porter, Richard Miles, Ch. Marlot, R. Cósias, S. Radaelli, B. Bayle, V. Ladino, C. Leyrat, P. Rodas, A. Klotz, R. Dusser, J. Clérigo, B. Wilson, E. Bredner, D. Cornwall, D. Ford, O. Labrevoir, D. Fernández, W. Barrow, Erika Castro, Bruno Sicardy, M. Mascaró, O. Chaptal, E. Simian, E. Recalde, B. Stephanus, Ricard Casas, F. Tonel, William Thuillot, V. Desnoux, J. Berthier, C. Oliveira, J. Laurindo Sobrinho, M. Rieugnié, P. Henriquet, J. Piraux, P. Rosenzweig, Steven N. Ward, G. Eleizalde, A. Yajamín, C. Sauzeaud, J. Aloy Doménech, K. Vieira, M. Lavayssière, P. Langlais, T. Rafaelli, G. Bouderand, J. Santiago, R. Delmas, M. Imbert, H. Denzau, J. A. Ros, A. Valencia, T. Lizardo, F. Teodoro de Gois, J. Porto, J. Fulgence, J.-P. Cazard, O. Contreras, F. Moreno, W. Beisker, J. Lockhart, T. Platt, F. Gorry, J. Afonso da Silva Mendes, R. Percz, R. Nunes, E. Guzmán, V. Ferrer, D. Dunham, S. Bumgarner, J. Fernández-Arozena, A.M. Blommers, C. Jasinski, O. Canales-Moreno, C. Reis, L.L. Martín-Rodríguez, M. Joaquim, O. Naranjo, D. Marchais, Thomas Widemann, C. Cremaschini, P.O. Pujat, and C. Cavadore
Subjects: Physics, 010504 meteorology & atmospheric sciences, Uranus, Astronomy, Astronomy and Astrophysics, Solar radius, Radius, Ephemeris, 01 natural sciences, Occultation, Atmosphere, 13. Climate action, Space and Planetary Science, Angular diameter, 0103 physical sciences, Physical Sciences, Polar, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: On September 8, 2001 around 2 h UT, the largest uranian moon, Titania, occulted Hipparcos star 106829 (alias SAO 164538, a V = 7.2 , K0 III star). This was the first-ever observed occultation by this satellite, a rare event as Titania subtends only 0.11 arcsec on the sky. The star's unusual brightness allowed many observers, both amateurs or professionals, to monitor this unique event, providing fifty-seven occultations chords over three continents, all reported here. Selecting the best 27 occultation chords, and assuming a circular limb, we derive Titania's radius: R T = 788.4 ± 0.6 km ( 1 - σ error bar). This implies a density of ρ = 1.711 ± 0.005 g cm −3 using the value G M = ( 2.343 ± 0.006 ) × 10 11 m 3 s −2 derived by Taylor [Taylor, D.B., 1998. Astron. Astrophys. 330, 362–374]. We do not detect any significant difference between equatorial and polar radii, in the limit r eq − r po = − 1.3 ± 2.1 km , in agreement with Voyager limb image retrieval during the 1986 flyby. Titania's offset with respect to the DE405 + URA027 (based on GUST86 theory) ephemeris is derived: Δ α T cos ( δ T ) = − 108 ± 13 mas and Δ δ T = − 62 ± 7 mas (ICRF J2000.0 system). Most of this offset is attributable to a Uranus' barycentric offset with respect to DE405, that we estimate to be: Δ α U cos ( δ U ) = − 100 ± 25 mas and Δ δ U = − 85 ± 25 mas at the moment of occultation. This offset is confirmed by another Titania stellar occultation observed on August 1st, 2003, which provides an offset of Δ α T cos ( δ T ) = − 127 ± 20 mas and Δ δ T = − 97 ± 13 mas for the satellite. The combined ingress and egress data do not show any significant hint for atmospheric refraction, allowing us to set surface pressure limits at the level of 10–20 nbar. More specifically, we find an upper limit of 13 nbar ( 1 - σ level) at 70 K and 17 nbar at 80 K, for a putative isothermal CO2 atmosphere. We also provide an upper limit of 8 nbar for a possible CH4 atmosphere, and 22 nbar for pure N2, again at the 1 - σ level. We finally constrain the stellar size using the time-resolved star disappearance and reappearance at ingress and egress. We find an angular diameter of 0.54 ± 0.03 mas (corresponding to 7.5 ± 0.4 km projected at Titania). With a distance of 170 ± 25 parsecs, this corresponds to a radius of 9.8 ± 0.2 solar radii for HIP 106829, typical of a K0 III giant.
Published: 2009

24. Venus Doppler winds at cloud tops observed with ESPaDOnS at CFHT

Author: Thomas Widemann, Jean-François Donati, Emmanuel Lellouch, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-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), 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: 010504 meteorology & atmospheric sciences, Venus, 01 natural sciences, Spectral line, law.invention, Mesosphere, Telescope, symbols.namesake, Phase angle (astronomy), law, 0103 physical sciences, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Spacecraft, biology, business.industry, [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Astronomy, Astronomy and Astrophysics, biology.organism_classification, Fraunhofer lines, 13. Climate action, Space and Planetary Science, symbols, business, Doppler effect
Abstract: International audience; We present new wind measurements in Venus' lower mesosphere from visible spectroscopy during the 2007 worldwide coordinated ground campaign in support of ESA's Venus Express mission. These observations consisted of high-resolution spectra of Fraunhofer lines in the entire visible range (0.37 1.05 μm) to measure the winds near 68 km using the Doppler shift of solar radiation scattered by clouds toward the observer's direction. The observations included various points of the dayside hemisphere at a phase angle of ˜109°. We took advantage of two symmetrical elongations in July and September 2007 at Canada France Hawaii's 3.6-m telescope. Kinematical fits to the Doppler winds provide a mean equatorial velocity of (104±10) m s‑1 for the zonal retrograde flow. This velocity agrees quite well with the mean value obtained by tracking the UV markings from several spacecraft.
Published: 2008

25. Charon's size and an upper limit on its atmosphere from a stellar occultation

Author: Jean Lecacheux, J-F Lecampion, O. Mousis, Daniela Lazzaro, S. Renner, D. N. da Silva Neto, E. Hummel, C. Jacques, E. Pimentel, Carlos Feinstein, Gonzalo Tancredi, B Gaillard, R. Vieira Martins, Alvaro Alvarez-Candal, M. Lavayssière, Marcelo Assafin, S. Lacour, H. Levato, F. Mallia, E. Frappa, O. Marco, Emmanuel Lellouch, C. H. Veiga, Olivier Hainaut, François Colas, Françoise Roques, T Momiyama, F Doncel, Frédéric Vachier, S. Pau, F Carrier, Eric Gendron, M. di Sora, Philippe Rousselot, Bruno Sicardy, W. Beisker, Alexandre Humberto Andrei, D. Weaver, Gianluca Masi, N. Ageorges, Raoul Behrend, Francois Lacombe, Thomas Widemann, A. Bellucci, Alain Maury, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Multidisciplinary, Pluto, 010504 meteorology & atmospheric sciences, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Satellites, Ciencias Físicas, Moons of Pluto, Astronomy, Radius, Mass ratio, Charon, 01 natural sciences, 7. Clean energy, Occultation, Astronomía, Atmosphere, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Planet, 0103 physical sciences, 010303 astronomy & astrophysics, CIENCIAS NATURALES Y EXACTAS, 0105 earth and related environmental sciences, Double planet
Abstract: Pluto and its satellite, Charon (discovered in 1978; ref. 1), appear to form a double planet, rather than a hierarchical planet/satellite couple. Charon is about half Pluto's size and about one-eighth its mass. The precise radii of Pluto and Charon have remained uncertain, leading to large uncertainties on their densities2. Although stellar occultations by Charon are in principle a powerful way of measuring its size, they are rare, as the satellite subtends less than 0.3 microradians (0.06 arcsec) on the sky. One occultation (in 1980) yielded a lower limit of 600 km for the satellite's radius 3, which was later refined to 601.5 km (ref. 4). Here we report observations from a multi-station stellar occultation by Charon, which we use to derive a radius, RC = 603.6 ± 1.4 km (1σ), and a density of ρ = 1.71 ± 0.08 g cm-3. This occultation also provides upper limits of 110 and 15 (3σ) nanobar for an atmosphere around Charon, assuming respectively a pure nitrogen or pure methane atmosphere. © 2006 Nature Publishing Group. Fil: Sicardy, B.. Universite Pierre et Marie Curie; Francia. Gepi - Galaxies, Etoiles, Physique, Instrumentation; Fil: Bellucci, A.. Gepi - Galaxies, Etoiles, Physique, Instrumentation; Fil: Gendron, E.. Gepi - Galaxies, Etoiles, Physique, Instrumentation; Fil: Lacombe, F.. Gepi - Galaxies, Etoiles, Physique, Instrumentation; Fil: Lacour, S.. Gepi - Galaxies, Etoiles, Physique, Instrumentation; Fil: Lecacheux, J.. Gepi - Galaxies, Etoiles, Physique, Instrumentation; Fil: Lellouch, E.. Gepi - Galaxies, Etoiles, Physique, Instrumentation; Fil: Renner, S.. Gepi - Galaxies, Etoiles, Physique, Instrumentation; Fil: Pau, S.. Gepi - Galaxies, Etoiles, Physique, Instrumentation; Fil: Roques, F.. Gepi - Galaxies, Etoiles, Physique, Instrumentation; Fil: Widemann, T.. Gepi - Galaxies, Etoiles, Physique, Instrumentation; Fil: Colas, F.. Imcce - Institut de Mecanique Celeste Et de Calcul Des Ephemerides; Fil: Vachier, F.. Imcce - Institut de Mecanique Celeste Et de Calcul Des Ephemerides; Fil: Martins, R. Vieira. Imcce - Institut de Mecanique Celeste Et de Calcul Des Ephemerides; . Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil Fil: Ageorges, N.. European Southern Observatory Santiago; Chile Fil: Hainaut, O.. European Southern Observatory Santiago; Chile Fil: Marco, O.. European Southern Observatory Santiago; Chile Fil: Beisker, W.. International Occultation Timing Association; Fil: Hummel, E.. International Occultation Timing Association; Fil: Feinstein Baigorri, Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; Argentina Fil: Levato, Orlando Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico ; Argentina Fil: Maury, A.. Gene Shoemaker Observatory; Chile Fil: Frappa, E.. Planétarium de Saint-etienne; Fil: Gaillard, B.. Association Des Utilisateurs de Détecteurs Electroniques (aude); Fil: Lavayssière, M.. Association Des Utilisateurs de Détecteurs Electroniques (aude); Fil: Di Sora, M.. Campo Catino Austral Observatory; Chile Fil: Mallia, F.. Campo Catino Austral Observatory; Chile Fil: Masi, G.. Campo Catino Austral Observatory; Chile. Universita Tor Vergata; Italia Fil: Behrend, R.. Universidad de Ginebra; Suiza Fil: Carrier, F.. Universidad de Ginebra; Suiza Fil: Mousis, O.. Observatoire de Besancon; Fil: Rousselot, P.. Observatoire de Besancon; Fil: Alvarez Candal, Alvaro Augusto. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil Fil: Lazzaro, D.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil Fil: Veiga, C.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil Fil: Andrei, A.H.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil. Universidade Federal do Rio de Janeiro; Brasil Fil: Assafin, M.. Universidade Federal do Rio de Janeiro; Brasil Fil: Da Silva Neto, D.N.. Universidade Federal do Rio de Janeiro; Brasil Fil: Jacques, C.. Observatório CEAMIG-REA; Brasil Fil: Pimentel, E.. Observatório CEAMIG-REA; Brasil Fil: Weaver, D.. Universidade de Fortaleza; Fil: Lecampion, J.-F.. Observatoire Aquitain Des Sciences de L'univers; Fil: Doncel, F.. Universidad Nacional de Asunción; Paraguay Fil: Momiyama, T.. Universidad Nacional de Asunción; Paraguay Fil: Tancredi, G.. Facultad de Ciencias; Uruguay
Published: 2006

26. An exploration of Pluto’s environment through stellar occultations

Author: O. Marco, D. N. da Silva Neto, Julio Camargo, Raoul Behrend, A. H. Andrei, A. Doressoundiram, F. Braga Ribas, Olivier Mousis, S. P. Littlefair, F. Roques, M. Kretlow, Valentin D. Ivanov, Philippe Rousselot, T. R. Marsh, Y. Boissel, V. S. Dhillon, R. Vieira Martins, Elena Mason, Nancy Ageorges, Bruno Sicardy, Thomas Widemann, Marcelo Assafin, Patrick Gaulme, 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), New Mexico State University, European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Max-Planck-Institut für Extraterrestrische Physik (MPE), Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), University of Sheffield [Sheffield], University of Warwick [Coventry], Observatório do Valongo/UFRJ [Rio de Janeiro], Universidade Federal do Rio de Janeiro (UFRJ), Observatorio Nacional [Rio de Janeiro], Centro Universitário Estadual da Zona Oeste [Rio de Janeiro] (UEZO), Geneva Observatory, University of Geneva [Switzerland], and International Occultation Timing Association (IOTA)
Subjects: Physics, New horizons, 010504 meteorology & atmospheric sciences, Dwarf planet, Astronomy, Astronomy and Astrophysics, Context (language use), Radius, Astrophysics, 01 natural sciences, Pluto, 13. Climate action, Space and Planetary Science, 0103 physical sciences, Stellar occultation, Limit (mathematics), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Equivalent width, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: Context. Pluto has five known satellites with diameters ranging from ~1200 km down to ~40 km, a possible outcome of a collisional origin. Smaller objects probably exist and may maintain tenuous rings, thus representing hazards during the New Horizons flyby of July 2015. Aims. The goal is to provide an upper limit for the numbers of unseen small bodies and/or equivalent widths of putative Pluto rings. Methods. We use a Pluto stellar appulse on April 10, 2006, and a stellar occultation by the dwarf planet on June 14, 2007, to scan Pluto’s surroundings. Results. Our best data set places a 3σ upper limit of 0.3 km for the radius of isolated moonlets that we can detect. In the absence of detection, we derive an upper limit of 15 000 for the number of such bodies at distances smaller than ~70 000 km from Pluto’s system barycenter. We place a 3σ upper limit of typically 30−100 m for the equivalent width of ring material at barycentric distances ranging from 13 000 to 70 000 km. This limit applies for narrow rings only, i.e. less than about 10 km in width
Published: 2014

27. HDO and SO2thermal mapping on Venus

Author: Sushil K. Atreya, John H. Lacy, Thierry Fouchet, Therese Encrenaz, Bruno Bézard, Matthew J. Richter, Thomas Widemann, Thomas K. Greathouse, and C. DeWitt
Subjects: Physics, 010504 meteorology & atmospheric sciences, biology, Terminator (solar), Imaging spectrometer, Astronomy, Astronomy and Astrophysics, Venus, Astrophysics, biology.organism_classification, 01 natural sciences, Mesosphere, Atmosphere of Venus, 13. Climate action, Space and Planetary Science, 0103 physical sciences, Mixing ratio, Spectral resolution, 010303 astronomy & astrophysics, Water vapor, 0105 earth and related environmental sciences
Abstract: Sulfur dioxide and water vapor, two key species of Venus photochemistry, are known to exhibit significant spatial and temporal variations above the cloud top. In particular, ground-based thermal imaging spectroscopy at high spectral resolution, achieved on Venus in January 2012, has shown evidence for strong SO2 variations on timescales shorter than a day. We have continued our observing campaign using the TEXES high-resolution imaging spectrometer at the NASA InfraRed Telescope Facility to map sulfur dioxide over the disk of Venus at two different wavelengths, 7 μm (already used in the previous study) and 19 μm. The 7 μm radiation probes the top of the H2SO4 cloud, while the 19 μm radiation probes a few kilometers below within the cloud. Observations took place on October 4 and 5, 2012. Both HDO and SO2 lines are identified in our 7-μm spectra and SO2 is also easily identified at 19 μm. The CO2 lines at 7 and 19 μm are used to infer the thermal structure. An isothermal/inversion layer is present at high latitudes (above 60 N and S) in the polar collars, which was not detected in October 2012. The enhancement of the polar collar in October 2012 is probably due to the fact that the morning terminator is observed, while the January data probed the evening terminator. As observed in our previous run, the HDO map is relatively uniform over the disk of Venus, with a mean mixing ratio of about 1 ppm. In contrast, the SO2 maps at 19 μm show intensity variations by a factor of about 2 over the disk within the cloud, less patchy than observed at the cloud top at 7 μm. In addition, the SO2 maps seem to indicate significant temporal changes within an hour. There is evidence for ac utoff in the SO2 vertical distribution above the cloud top, also previously observed by SPICAV/SOIR aboard Venus Express and predicted by photochemical models.
Published: 2013

28. THE SIZE, SHAPE, ALBEDO, DENSITY, AND ATMOSPHERIC LIMIT OF TRANSNEPTUNIAN OBJECT (50000) QUAOAR FROM MULTI-CHORD STELLAR OCCULTATIONS

Author: J. P. Colque, Alain Maury, R. Vieira-Martins, S. Roland, Paolo Tanga, Claudia V. Rodrigues, Leonardo A. Almeida, S. Sposetti, E. Frappa, Felipe Braga-Ribas, A. Amorim, P. Cacella, C. Jacques, Alain Klotz, Rodrigo Leiva, Gonzalo Tancredi, Joe Pollock, W. Beisker, L. Almenares, Estrella Álvarez, Jean Manfroid, William Schoenell, Marcelo Assafin, Michaël Gillon, Audrey Thirouin, François Colas, E. Pimentel, Julio Camargo, R. Salvo, Eduardo Unda-Sanzana, V. S. Magalhães, J. Capeche, Emmanuel Jehin, Ricardo Gil-Hutton, Emmanuel Lellouch, L. Vanzi, Frédéric Vachier, Breno L. Giacchini, Bruno Sicardy, C. Neves, Françoise Roques, Aaron P. LaCluyze, Rene Duffard, Thomas Widemann, Raoul Behrend, Sebastian Bruzzone, Daniel E. Reichart, A. Milone, K. M. Ivarsen, J. B. Haislip, C. E. Cedeño Montaña, Jose Luis Ortiz, Nicolás Morales, Marcelo Emilio, Jean Lecacheux, Ignacio Toledo, 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), Cátedra de Tecnología de la Madera. Departamento de Ingeniería Forestal (CTM-ETSIM), Universidad Politécnica de Madrid (UPM), Observatorio Nacional [Rio de Janeiro], Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Observatório do Valongo/UFRJ [Rio de Janeiro], Universidade Federal do Rio de Janeiro (UFRJ), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), San Pedro de Atacama Celestial Explorations (SPACE), San Pedro de Atacama Celestial Explorations, Universidade Estadual de Ponta Grossa, Universidade Estadual de Ponta Grossa - State University of Ponta Grossa (UEPG), Institute Patology and Imunology Molecular, Fac Ciencias, Universidade do Porto, Instituto de Astronomıa, universidad catolica del Norte, Institut Parisien de Chimie Moléculaire (IPCM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Observatório CEAMIG-REA, Universidad Nacional de San Juan (UNSJ), Instituto Nacional de Pesquisas Espaciais (INPE), Ministério da Ciência, Tecnologia e Inovação, European Southern Observatory (ESO), Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Gnosca Observatory, Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), 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), Euraster, Interactions et dynamique des environnements de surface (IDES), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Southwest Research Institute [Boulder] (SwRI), Joint ALMA Observatory (JAO), National Radio Astronomy Observatory (NRAO)-European Southern Observatory (ESO), International Occultation Timing Association European Section (IOTA ES), International Occultation Timing Association European Section, Department of Physics and Astronomy [Boone], Appalachian State University, University of North Carolina System (UNC)-University of North Carolina System (UNC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Université de Genève = University of Geneva (UNIGE), Universidade do Porto = University of Porto, Universidad Nacional de San Juan [Argentine] (UNSJ), Université Nice Sophia Antipolis (1965 - 2019) (UNS), 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), 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), and European Southern Observatory (ESO)-National Radio Astronomy Observatory (NRAO)
Subjects: Kuiper belt objects: individual: 50000 Quaoar, 010504 meteorology & atmospheric sciences, Ciencias Físicas, Astrophysics, 7. Clean energy, 01 natural sciences, Planet, TRANSNEPTUNIAN OBJECT, occultations, 0103 physical sciences, Trans-Neptunian object, planets and satellites: fundamental parameters, 010303 astronomy & astrophysics, KUIPER BELT OBJECTS, 0105 earth and related environmental sciences, planets and satellites: atmospheres, [PHYS]Physics [physics], Physics, Astronomy, Astronomy and Astrophysics, Astronomía, Stars, Space and Planetary Science, OCCULTATIONS, Chord (music), ATMOSPHERES, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], CIENCIAS NATURALES Y EXACTAS
Abstract: We present results derived from the first multi-chord stellar occultations by the transneptunian object (50000) Quaoar, observed on 2011 May 4 and 2012 February 17, and from a single-chord occultation observed on 2012 October 15. If the timing of the five chords obtained in 2011 were correct, then Quaoar would possess topographic features (crater or mountain) that would be too large for a body of this mass. An alternative model consists in applying time shifts to some chords to account for possible timing errors. Satisfactory elliptical fits to the chords are then possible, yielding an equivalent radius Requiv = 555±2.5 km and geometric visual albedo pV = 0.109±0.007. Assuming that Quaoar is a Maclaurin spheroid with an indeterminate polar aspect angle, we derive a true oblateness of = 0.087+0.0268 −0.0175, an equatorial radius of 569+24 −17 km, and a density of 1.99 ± 0.46 g cm−3. The orientation of our preferred solution in the plane of the sky implies that Quaoar’s satellite Weywot cannot have an equatorial orbit. Finally, we detect no global atmosphere around Quaoar, considering a pressure upper limit of about 20 nbar for a pure methane atmosphere. Fil: Braga Ribas, F.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil; . Laboratoire d; Fil: Sicardy, B.. Laboratoire d; . Universite Pierre Et Marie Curie; Francia; Fil: Ortiz, J. L.. Consejo Superior de Investigaciones Científicas. Instituto de Astrofísica de Andalucía; España; Fil: Lellouch, E.. Laboratoire d; Fil: Tancredi, G.. Observatorio Astronomico Los Molinos; Uruguay; Fil: Lecacheux, J.. Laboratoire d; Fil: Vieira Martins, R.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil; . L; . Universidade Federal Rural do Rio de Janeiro. Observatorio do Valongo; Brasil; Fil: Camargo, J. I. B.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil; Fil: Assafin, M.. Universidade Federal Rural do Rio de Janeiro. Observatorio do Valongo; Brasil; Fil: Behrend, R.. Observatoire de Geneve; Suiza; Fil: Vachier, F.. L; Fil: Colas, F.. L; Fil: Morales, N.. Consejo Superior de Investigaciones Científicas. Instituto de Astrofísica de Andalucía; España; Fil: Maury, A.. San Pedro de Atacama Celestial Explorations, Chile; Fil: Emilio, M.. Universidad Stadual de Ponta Grossa; Brasil; Fil: Amorim, A.. Universidade Federal Da Santa Catarina; Brasil; Fil: Unda Sanzana, E.. Universidad de Antofagasta. Unidad de Astronomía; Chile; Fil: Roland, S.. Observatorio Astronomico Los Molinos; Uruguay; Fil: Bruzzone, S.. Observatorio Astronomico Los Molinos; Uruguay; Fil: Almeida, L. A.. Centro de Previsao de Tempo e Estudos Climaticos. Instituto Nacional de Pesquisas Espaciais; Brasil; Fil: Rodrigues, C. V.. Centro de Previsao de Tempo e Estudos Climaticos. Instituto Nacional de Pesquisas Espaciais; Brasil; Fil: Jacques, C.. Centro de Estudos Astronomicos de Minas Gerais; Brasil; Fil: Gil Hutton, Ricardo Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - San Juan. Complejo Astronómico; Argentina Fil: Vanzi, L.. Pontificia Universidad Católica de Chile. Department of Electrical Engineering and Center of Astro-Engineering; Chile; Fil: Milone, A. C.. Centro de Previsao de Tempo e Estudos Climaticos. Instituto Nacional de Pesquisas Espaciais; Brasil; Fil: Schoenell, W.. Consejo Superior de Investigaciones Científicas. Instituto de Astrofísica de Andalucía; España; . Universidade Federal Da Santa Catarina; Brasil; Fil: Salvo, R.. Observatorio Astronomico Los Molinos; Uruguay; Fil: Almenares, L.. Observatorio Astronomico Los Molinos; Uruguay; Fil: Jehin, E. Université de Liège. Institut d’Astrophysique; Belgica; Fil: Manfroid, J.. Université de Liège. Institut d’Astrophysique; Belgica; Fil: Sposetti, S.. Gnosca Observatory, Suiza; Fil: Tanga, P.. Observatoire de la Cote D; . Universite de Sophia Antipolis. Laboratoire Lagrange; Francia; Fil: Klotz, A.. Université Toulouse III “Paul Sabatier”. Observatoire Midi-Pyrénées. Institut de Recherche en Astrophysique et Planétologie; Francia; Fil: Frappa, E.. Euraster, Francia; Fil: Cacella, P.. Rede de Astronomia Observacional; Brasil; Fil: Colque, J. P.. Universidad de Antofagasta. Unidad de Astronomía; Chile; Fil: Neves, C.. Universidad Stadual de Ponta Grossa; Brasil; Fil: Alvarez, E. M.. Observatorio Los Algarrobos, Uruguay; Fil: Gillon, M.. Université de Liège. Institut d’Astrophysique; Belgica; Fil: Pimentel, E.. Centro de Estudos Astronomicos de Minas Gerais; Brasil; Fil: Giacchini, B.. Centro de Estudos Astronomicos de Minas Gerais; Brasil; Fil: Roques, F.. Laboratoire d; Fil: Widemann, T.. Laboratoire d; Fil: Magalhães, V. S.. Centro de Previsao de Tempo e Estudos Climaticos. Instituto Nacional de Pesquisas Espaciais; Brasil; Fil: Thirouin, A.. Consejo Superior de Investigaciones Científicas. Instituto de Astrofísica de Andalucía; España; Fil: Duffard, Rene Damian. Centro Informático Científico de Andalucía; España; . Consejo Superior de Investigaciones Científicas. Instituto de Astrofísica de Andalucía; España; Fil: Leiva, R.. Pontificia Universidad Católica de Chile. Department of Electrical Engineering and Center of Astro-Engineering; Chile; Fil: Toledo, I.. Joint Atacama Large Millimeter/submillimeter Array Observatory; Chile; Fil: Capeche, J.. Observatorio Astronomico Los Molinos; Uruguay; Fil: Beisker, W.. International Occultation Timing Association European Section; Alemania; Fil: Pollock, J.. Appalachian State University. Department of Physics and Astronomy; Estados Unidos; Fil: Cedeno Montaña, C. E.. Centro de Previsao de Tempo e Estudos Climaticos. Instituto Nacional de Pesquisas Espaciais; Brasil; Fil: Ivarsen, K. University of North Carolina. Physics and Astronomy Department; Estados Unidos; Fil: Reichart, D.. University of North Carolina. Physics and Astronomy Department; Estados Unidos; Fil: Haislip, J.. University of North Carolina. Physics and Astronomy Department; Estados Unidos; Fil: Lacluyze, A.. University of North Carolina. Physics and Astronomy Department; Estados Unidos
Published: 2013

29. CONSTRAINTS ON CHARON'S ORBITAL ELEMENTS FROM THE DOUBLE STELLAR OCCULTATION OF 2008 JUNE 22

Author: T. Dobosz, J. G. Greenhill, Marcelo Assafin, Bruno Sicardy, D. Buckley, W. Beisker, Greg Bolt, F. Benard, V. Batista, J.-P. Teng-Chuen-Yu, François Colas, Alain Doressoundiram, C. Gruhn, J. Broughton, J. Lecacheux, S. Mathers, Julio Camargo, Roberto Vieira-Martins, D. Gault, A. Peyrot, A. H. Andrei, J. Biggs, C. De Witt, B. Lade, S. Dieters, Dave Herald, Felipe Braga-Ribas, D. N. da Silva Neto, R. Groom, Y. Boissel, E. Frappa, Thomas Widemann, S. Kerr, F. Roques, Raoul Behrend, 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), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Craigie, Reedy Creek, Bankstown, International Occulting and Timing Association (IOTA), International Occulting and Timing Association, Astronomical Association of Queensland (AAQ), Association astronomique de la Réunion (AAR), Association astronomique de la Réunion, Euraster, International Occultation Timing Association European Section (IOTA ES), International Occultation Timing Association European Section, South African Astronomical Observatory (SAAO), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Springbok, International Amateur Sternwarte (IAS), International Amateur Sternwarte, Institut d'Astrophysique de Paris (IAP), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Perth Observatory, School of Mathematics and Physics, University of Tasmania [Hobart, Australia] (UTAS), Astronomical Society of Western Australia (ASWA), Canberra Astronomical Society, Stockport Observatory, Southern Cross Observatory, Observatório do Valongo/UFRJ [Rio de Janeiro], Universidade Federal do Rio de Janeiro (UFRJ), Observatório Nacional/MCT, Universidade Estadual da Zona Oeste (UEZO), Universidade Estadual da Zona Oeste, Geneva Observatory, University of Geneva [Switzerland], Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Université de Genève = University of Geneva (UNIGE)
Subjects: Physics, Orbital elements, Orbital plane, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Orbital node, Equator, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astronomy, Astronomy and Astrophysics, Astrophysics, Ephemeris, 01 natural sciences, Pluto, True longitude, Kuiper belt objects : individual : Pluto Charon, planets and satellites : fundamental parameters, Space and Planetary Science, occultations, 0103 physical sciences, astrometry, Longitude, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: The original publication is available at http://iopscience.iop.org/1538-3881/; International audience; Pluto and its main satellite, Charon, occulted the same star on 2008 June 22. This event was observed from Australia and La Réunion Island, providing the east and north Charon Plutocentric offset in the sky plane (J2000): X= + 12,070.5 ± 4 km (+ 546.2 ± 0.2 mas), Y= + 4,576.3 ± 24 km (+ 207.1 ± 1.1 mas) at 19:20:33.82 UT on Earth, corresponding to JD 2454640.129964 at Pluto. This yields Charon's true longitude L= 153.483 ± 0fdg071 in the satellite orbital plane (counted from the ascending node on J2000 mean equator) and orbital radius r= 19,564 ± 14 km at that time. We compare this position to that predicted by (1) the orbital solution of Tholen & Buie (the "TB97" solution), (2) the PLU017 Charon ephemeris, and (3) the solution of Tholen et al. (the "T08" solution). We conclude that (1) our result rules out solution TB97, (2) our position agrees with PLU017, with differences of ΔL= + 0.073 ± 0fdg071 in longitude, and Δr= + 0.6 ± 14 km in radius, and (3) while the difference with the T08 ephemeris amounts to only ΔL= 0.033 ± 0fdg071 in longitude, it exhibits a significant radial discrepancy of Δr= 61.3 ± 14 km. We discuss this difference in terms of a possible image scale relative error of 3.35 × 10-3in the 2002-2003 Hubble Space Telescope images upon which the T08 solution is mostly based. Rescaling the T08 Charon semi-major axis, a = 19, 570.45 km, to the TB97 value, a = 19636 km, all other orbital elements remaining the same ("T08/TB97" solution), we reconcile our position with the re-scaled solution by better than 12 km (or 0.55 mas) for Charon's position in its orbital plane, thus making T08/TB97 our preferred solution.
Published: 2011

30. VEGA 1 and VEGA 2 entry probes: An investigation of local UV absorption (220-400 nm) in the atmosphere of Venus (SO2, aerosols, cloud structure)

Author: V. I. Moroz, Thomas Widemann, A. P. Ekonomov, Alain Hauchecorne, Jean-Loup Bertaux, Service d'aéronomie (SA), 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), Space Research Institute of the Russian Academy of Sciences (IKI), and Russian Academy of Sciences [Moscow] (RAS)
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, Cloud cover, Soil Science, Venus, Aquatic Science, Oceanography, 01 natural sciences, Atmosphere of Venus, Altitude, Geochemistry and Petrology, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Mixing ratio, Absorption (electromagnetic radiation), 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Earth-Surface Processes, Water Science and Technology, Physics, Ecology, biology, Nephelometer, Paleontology, Astronomy, Forestry, biology.organism_classification, Wavelength, Geophysics, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics]
Abstract: International audience; In 1985 the VEGA 1 and VEGA 2 spacecraft dropped two descent probes into the nightside of Venus. On board was the French-Russian ISAV ultraviolet spectroscopy experiment, consisting of a UV light source absorbed by atmospheric constituents circulating freely into a tube attached outside the pressurized modules. ISAV generated a wealth of absorption spectra in the 220- to 400-nm range with an unprecedented vertical resolution (60-170 m) from 62 km of altitude down to the ground. On the basis of known instrument properties and a careful examination of the light curves recorded in 13 wavelength intervals in the UV, we show that most of the recorded differential absorption (at each wavelength with respect to 394 nm) can be explained by a combination of gaseous SO2 absorption and absorption by aerosols deposited on the mirrors during the crossing of Venus' lower cloud. The spectral signature of this absorber, termed X, was obtained, thanks to an unexpected shock on VEGA 1 which removed this absorber from the mirrors at 18 km of altitude. The UV spectral signature of X resembles that of croconic acid, C5O5H2, whose absorbing power as a contaminant of H2SO4 droplets at 2.5% dilution is compatible with the observations. However, the nonidentity of the spectral signature, together with stability arguments, makes this identification less plausible. Whatever its nature, the relevance of this new absorber X is discussed in connection with the albedo of Venus and the IR variable leak windows. If this absorber X detected by ISAV in the lower cloud were also present in the upper cloud, it would be a good candidate to explain the UV part (λ

31. The Venus Emissivity Mapper (VEM) concept

Author: Emmanuel Marcq, Judit Jaenchen, Alessandro Maturilli, Nils Mueller, Sabrina Ferrari, Anko Boerner, Ingo Walter, Joern Helbert, Suzanne E. Smrekar, Gabriele Arnold, Mario D'Amore, Thomas Widemann, Dennis Wendler, Gabriel Guignan, Darby Dyar, David Kappel, and Strojnik, Marija
Subjects: Asteroiden und Kometen, spectroscopy, 010504 meteorology & atmospheric sciences, Multispectral image, near infrared, Venus, 01 natural sciences, 7. Clean energy, law.invention, Hochgeschwindigkeitselektronik, Mission design, law, 0103 physical sciences, Emissivity, Radar, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Remote sensing, Echtzeit-Datenprozessierung, biology, Spacecraft, business.industry, Leitungsbereich PF, biology.organism_classification, Planetary science, Planetare Sensorsysteme, business, Geology
Abstract: Based on experience gained from using the VIRTIS instrument on Venus Express to observe the surface of Venus and the new high temperature laboratory experiments, we have developed the multispectral Venus Emissivity Mapper (VEM) to study the surface of Venus. VEM imposes minimal requirements on the spacecraft and mission design and can therefore be added to any future Venus mission. Ideally, the VEM instrument will be combined with a high-resolution radar mapper to provide accurate topographic information, as it will be the case for the NASA Discovery VERITAS mission or the ESA EnVision M5 proposal.
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32. Study of the Plutino Object (208996) 2003 AZ 84 from Stellar Occultations: Size, Shape, and Topographic Features

Author: A. Klotz, Julio Camargo, T. Hayamizu, Shashikiran Ganesh, Noah Brosch, Felipe Braga-Ribas, Avishay Gal-Yam, Paolo Tanga, J. L. Ortiz, J. Bradshaw, S. Andersson, G. Dangl, H. Tomioka, Rodrigo Leiva, Marcelo Assafin, A. Sharma, Andrea Richichi, Emmanuel Jehin, S. Sposetti, Tapas Baug, Frédéric Vachier, Zhao Ergang, T. Chandrasekhar, Zhu Liying, H. Yamamura, Shai Kaspi, Hayato Watanabe, Puji Irawati, E. Frappa, R. Naves, Eran O. Ofek, Thomas Widemann, Zouhair Benkhaldoun, Nora Morales, C. Rinner, Qian Shengbang, Alain Maury, Pablo Santos-Sanz, Ilan Manulis, Rene Duffard, Yasukazu Ikari, S. Kerr, A. Dias-Oliveira, Raoul Behrend, Jean Manfroid, Vishnu Mohan, J. Jain, Audrey Thirouin, G. Wortmann, A. Daassou, A. R. Gomes-Junior, Michaël Gillon, Hiroyuki Watanabe, Jean Lecacheux, G. Benedetti-Rossi, P. Mahasena, M. Owada, Josselin Desmars, Roberto Vieira-Martins, A. Asai, R. Garcia-Lozano, Bruno Sicardy, T. Haymes, 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), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-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), Observatorio Nacional [Rio de Janeiro], Observatório Nacional/MCT, Observatório do Valongo/UFRJ [Rio de Janeiro], Universidade Federal do Rio de Janeiro (UFRJ), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Physical Research Laboratory [Ahmedabad] (PRL), and Indian Space Research Organisation (ISRO)
Subjects: Rotation period, Chord (geometry), [PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], Astrophysics, Rotation, 01 natural sciences, Occultation, law.invention, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, Geometric albedo, law, 0103 physical sciences, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Physics, [PHYS]Physics [physics], Astronomy and Astrophysics, Light curve, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], Amplitude, Space and Planetary Science, Hydrostatic equilibrium, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], [PHYS.PHYS.PHYS-DATA-AN]Physics [physics]/Physics [physics]/Data Analysis, Statistics and Probability [physics.data-an], Astrophysics - Earth and Planetary Astrophysics
Abstract: We present results derived from four stellar occultations by the plutino object (208996) 2003~AZ$_{84}$, detected at January 8, 2011 (single-chord event), February 3, 2012 (multi-chord), December 2, 2013 (single-chord) and November 15, 2014 (multi-chord). Our observations rule out an oblate spheroid solution for 2003~AZ$_{84}$'s shape. Instead, assuming hydrostatic equilibrium, we find that a Jacobi triaxial solution with semi axes $(470 \pm 20) \times (383 \pm 10) \times (245 \pm 8)$~km % axis ratios $b/a= 0.82 \pm 0.05$ and $c/a= 0.52 \pm 0.02$, can better account for all our occultation observations. Combining these dimensions with the rotation period of the body (6.75~h) and the amplitude of its rotation light curve, we derive a density $��=0.87 \pm 0.01$~g~cm$^{-3}$ a geometric albedo $p_V= 0.097 \pm 0.009$. A grazing chord observed during the 2014 occultation reveals a topographic feature along 2003~AZ$_{84}$'s limb, that can be interpreted as an abrupt chasm of width $\sim 23$~km and depth $> 8$~km or a smooth depression of width $\sim 80$~km and depth $\sim 13$~km (or an intermediate feature between those two extremes).
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32 results on '"Thomas Widemann"'

1. Venus: key to understanding the evolution of terrestrial planets

2. A Wind Study of Venus’s Cloud Top: New Doppler Velocimetry Observations

3. HDO and SO2 thermal mapping on Venus

4. A stringent upper limit on the PH3 abundance at the cloud top of Venus

5. Atmospheric circulation of Venus measured with visible imaging spectroscopy at the THEMIS observatory

6. Lower atmosphere and pressure evolution on Pluto from ground-based stellar occultations, 1988–2016

7. HDO and SO2 thermal mapping on Venus. IV. Statistical analysis of the SO2 plumes

8. The Venus Emissivity Mapper (VEM): Obtaining global mineralogy of Venus from orbit

9. Search for horizontal and vertical variations of CO in the day and night side lower mesosphere of Venus from CSHELL/IRTF 4.53μm observations

10. The Venus Emissivity Mapper concept

11. Venus cloud-tracked and doppler velocimetry winds from CFHT/ESPaDOnS and Venus Express/VIRTIS in April 2014

12. Mapping the thermal structure and minor species of Venus mesosphere with ALMA submillimeter observations

13. HDO and SO 2 thermal mapping on Venus. III. Short-term and long-term variations between 2012 and 2016

14. Albedo and atmospheric constraints of dwarf planet Makemake from a stellar occultation

15. A ring system detected around the Centaur (10199) Chariklo

16. Instrumental Methods for Professional and Amateur Collaborations in Planetary Astronomy

17. Mapping zonal winds at Venus’s cloud tops from ground-based Doppler velocimetry

18. HDO and SO 2 thermal mapping on Venus: evidence for strong SO 2 variability

19. Sunlight refraction in the mesosphere of Venus during the transit on June 8th, 2004

20. A Pluto-like radius and a high albedo for the dwarf planet Eris from an occultation

21. Transmission spectrum of Venus as a transiting exoplanet

22. The science of EChO

23. Titania's radius and an upper limit on its atmosphere from the September 8, 2001 stellar occultation

24. Venus Doppler winds at cloud tops observed with ESPaDOnS at CFHT

25. Charon's size and an upper limit on its atmosphere from a stellar occultation

26. An exploration of Pluto’s environment through stellar occultations

27. HDO and SO2thermal mapping on Venus

28. THE SIZE, SHAPE, ALBEDO, DENSITY, AND ATMOSPHERIC LIMIT OF TRANSNEPTUNIAN OBJECT (50000) QUAOAR FROM MULTI-CHORD STELLAR OCCULTATIONS

29. CONSTRAINTS ON CHARON'S ORBITAL ELEMENTS FROM THE DOUBLE STELLAR OCCULTATION OF 2008 JUNE 22

30. VEGA 1 and VEGA 2 entry probes: An investigation of local UV absorption (220-400 nm) in the atmosphere of Venus (SO2, aerosols, cloud structure)

31. The Venus Emissivity Mapper (VEM) concept

32. Study of the Plutino Object (208996) 2003 AZ 84 from Stellar Occultations: Size, Shape, and Topographic Features

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32 results on '"Thomas Widemann"'

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