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9 results on '"DLR Institut für Planetenerkundung"'

1. Removing systematics from the CoRoT light curves: I. Magnitude-Dependent Zero Point

Author

T. Mazeh, P. Guterman, S. Aigrain, S. Zucker, N. Grinberg, A. Alapini, R. Alonso, M. Auvergne, M. Barbieri, P. Barge, P. Bordé, F. Bouchy, H. Deeg, R. De la Reza, M. Deleuil, R. Dvorak, A. Erikson, M. Fridlund, P. Gondoin, L. Jorda, H. Lammer, A. Léger, A. Llebaria, P. Magain, C. Moutou, M. Ollivier, M. Pätzold, F. Pont, D. Queloz, H. Rauer, D. Rouan, R. Sabo, J. Schneider, G. Wuchterl, Radcliffe Institute for Advanced Study, 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), University of Exeter, Tel Aviv University (TAU), 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 d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Observatoire de Haute-Provence (OHP), Institut Pythéas (OSU PYTHEAS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Instituto de Astrofisica de Canarias (IAC), Observatório Nacional/MCTI, Institut für Astronomie, Universität Wien (IfA), DLR Institut für Planetenerkundung, Research and Scientific Support Department, ESA-ESTEC (RSSD), Institut für Weltraumforschung, Österreichische Akademie der Wissenschaften (IWF), University of Liège, Rheinisches Institut für Umweltforschung an der Universität zu Köln (RIU), Observatoire Astronomique de l'Université de Genève, Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Zentrum für Astronomie und Astrophysik, Technische Universität Berlin (TUB) (ZAA)

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Physics, photometry, Field (physics), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Zero-point energy, Astronomy and Astrophysics, Astrophysics, Function (mathematics), Light curve, Exoplanet, CoRoT, Apparent magnitude, exoplanets, transit method, Space and Planetary Science, Magnitude (astronomy), Outlier, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], systematic noise, Astrophysics - Earth and Planetary Astrophysics
Abstract

This paper presents an analysis that searched for systematic effects within the CoRoT exoplanet field light curves. The analysis identified a systematic effect that modified the zero point of most CoRoT exposures as a function of stellar magnitude. We could find this effect only after preparing a set of learning light curves that were relatively free of stellar and instrumental noise. Correcting for this effect, rejecting outliers that appear in almost every exposure, and applying SysRem, reduced the stellar RMS by about 20 %, without attenuating transit signals., Accepted for publication in Astronomy and Astrophysics

Published
2016
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2. Implications of Rotation, Orbital States, Energy Sources, and Heat Transport for Internal Processes in Icy Satellites

Author

Tim Van Hoolst, Dennis L. Matson, Valéry Lainey, Gaël Choblet, Hauke Hussmann, Gabriel Tobie, Christophe Sotin, DLR Institut für Planetenerkundung, 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), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Groupe Astrométrie et Planétologie (GAP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Jet Propulsion Laboratory, California Institute of Technology (JPL), and Observatoire Royal de Belgique (ORB)

Subjects
Physics, Convection, Solar System, Convective heat transfer, Satellites, Astronomy, Astronomy and Astrophysics, rotation, orbital dynamics, Accretion (astrophysics), Astrobiology, Space and Planetary Science, Planet, tides, heat transfer, Physics::Space Physics, Heat transfer, Satellite, Astrophysics::Earth and Planetary Astrophysics, Energy source, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], energy sources, Physics::Atmospheric and Oceanic Physics
Abstract

International audience; Internal processes in icy satellites, e.g. the exchange of material from the subsurface to the surface or processes leading to volcanism and resurfacing events, are a consequence of the amount of energy available in the satellites' interiors. The latter is mainly determined shortly after accretion by the amount of radioactive isotopes incorporated in the silicates during the accretion process. However, for satellites---as opposed to single objects---important contributions to the energy budget on long time-scales can come from the interaction with other satellites (forcing of eccentricities of satellites in resonance) and consequently from the tidal interaction with the primary planet. Tidal evolution involves both changes of the rotation state---usually leading to the 1:1 spin orbit coupling---and long-term variations of the satellite orbits. Both processes are dissipative and thus connected with heat production in the interior. The way heat is transported from the interior to the surface (convection, conduction, (cryo-) volcanism) is a second main aspect that determines how internal processes in satellites work. In this chapter we will discuss the physics of heat production and heat transport as well as the rotational and orbital states of satellites. The relevance of the different heat sources for the moons in the outer solar system are compared and discussed.

Published
2010
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3. Noise properties of the CoRoT data: a planet-finding perspective

Author

P. Gondoin, Helmut Lammer, M. Auvergne, Anders Erikson, Heike Rauer, M. Fridlund, Shay Zucker, P. Guterman, D. Rouan, Pierre Magain, A. Alapini, Francois Fressin, Suzanne Aigrain, Roi Alonso, Laurent Jorda, Rudolf Dvorak, Didier Queloz, Marc Ollivier, Antoine Llebaria, M. Barbieri, G. Wuchter, Pascal Bordé, Martin Pätzold, R. de la Reza, François Bouchy, Jean Schneider, Tsevi Mazeh, Pierre Barge, A. Léger, C. Moutou, Hans J. Deeg, Frederic Pont, Magali Deleuil, University of Exeter, Harvard-Smithsonian Center for Astrophysics, 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 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 d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Observatoire de Haute-Provence (OHP), Institut Pythéas (OSU PYTHEAS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Instituto de Astrofisica de Canarias (IAC), Observatório Nacional/MCTI, Institut für Astronomie, Universität Wien (IfA), DLR Institut für Planetenerkundung, Research and Scientific Support Department, ESA-ESTEC (RSSD), Institut für Weltraumforschung, Österreichische Akademie der Wissenschaften (IWF), University of Liège, Tel Aviv University (TAU), Rheinisches Institut für Umweltforschung an der Universität zu Köln (RIU), Observatoire Astronomique de l'Université de Genève, Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Thüringer Landessternwarte, Tautenburg Observatory

Subjects
noise, photometry, Population, transit search, FOS: Physical sciences, Astrophysics, Filter (large eddy simulation), Planet, Astrophysics::Solar and Stellar Astrophysics, education, Instrumentation and Methods for Astrophysics (astro-ph.IM), Solar and Stellar Astrophysics (astro-ph.SR), Physics, Earth and Planetary Astrophysics (astro-ph.EP), education.field_of_study, Astronomy and Astrophysics, Planetary system, Light curve, CoRoT, Stars, Astrophysics - Solar and Stellar Astrophysics, exoplanets, Space and Planetary Science, transit method, Magnitude (astronomy), Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Noise (radio), Astrophysics - Earth and Planetary Astrophysics
Abstract

In this short paper, we study the photometric precision of stellar light curves obtained by the CoRoT satellite in its planet finding channel, with a particular emphasis on the timescales characteristic of planetary transits. Together with other articles in the same issue of this journal, it forms an attempt to provide the building blocks for a statistical interpretation of the CoRoT planet and eclipsing binary catch to date. After pre-processing the light curves so as to minimise long-term variations and outliers, we measure the scatter of the light curves in the first three CoRoT runs lasting more than 1 month, using an iterative non-linear filter to isolate signal on the timescales of interest. The bevhaiour of the noise on 2h timescales is well-described a power-law with index 0.25 in R-magnitude, ranging from 0.1mmag at R=11.5 to 1mmag at R=16, which is close to the pre-launch specification, though still a factor 2-3 above the photon noise due to residual jitter noise and hot pixel events. There is evidence for a slight degradation of the performance over time. We find clear evidence for enhanced variability on hours timescales (at the level of 0.5 mmag) in stars identified as likely giants from their R-magnitude and B-V colour, which represent approximately 60 and 20% of the observed population in the direction of Aquila and Monoceros respectively. On the other hand, median correlated noise levels over 2h for dwarf stars are extremely low, reaching 0.05mmag at the bright end., Comment: 5 pages, 4 figures, accepted for publication in A&A

Published
2009
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4. VIMS spectral mapping observations of Titan during the Cassini prime mission

Author

Laurence A. Soderblom, Angioletta Coradini, Priscilla Cerroni, Dale P. Cruikshank, Ralf Jaumann, Caitlin A. Griffith, Katrin Stephan, Vittorio Formisano, Dennis L. Matson, Thomas B. McCord, Jason M. Soderblom, Roger N. Clark, Pierre Drossart, K. M. Pitman, P. D. Nicholson, Bruno Sicardy, Paulo Penteado, Paul O. Hayne, Bonnie J. Buratti, G. Vixie, Yves Langevin, Jean-Pierre Bibring, Christophe Sotin, Stéphane Le Mouélic, Robert H. Brown, Kevin H. Baines, Jason W. Barnes, Sebastien Rodriguez, Robert M. Nelson, Fabrizio Capaccioni, Giancarlo Bellucci, Federico Tosi, University of Idaho [Moscow, USA], Lunar and Planetary Laboratory [University of Arizona] (LPL), University of Arizona, Jet Propulsion Laboratory, California Institute of Technology (JPL), United States Geological Survey, Denver, DLR Institut für Planetenerkundung, Bear Fight Center, Space Science Institute, Winthrop, 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), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), United States Geological Survey, Astrogeology Division, Earth and Space Sciences Department, University of California, Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Istituto di Astrofisica Spaziale e Fisica Cosmica (IASF-Roma), SETI Institute, NASA Ames Research Center, Moffett Field, Observatoire de Paris, Université Paris sciences et lettres (PSL), 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), Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Department of Astronomy, Cornell University, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Planetary Science Institute [Tucson] (PSI), Institute of Geological Sciences [Berlin], Department of Earth Sciences [Berlin], Free University of Berlin (FU)-Free University of Berlin (FU), Bear Fight Institute, 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), 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), NASA Ames Research Center (ARC), Cornell University [New York], Pôle Astronomie du LESIA, 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)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris

Subjects
[PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astronomy and Astrophysics, Astrobiology, symbols.namesake, Spectral mapping, Space and Planetary Science, symbols, VIMS, Cassini, Titan (rocket family), Titan, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Geology, Remote sensing
Abstract

International audience; This is a data paper designed to facilitate the use of and comparisons to Cassini/visual and infrared mapping spectrometer (VIMS) spectral mapping data of Saturn's moon Titan. We present thumbnail orthographic projections of flyby mosaics from each Titan encounter during the Cassini prime mission, 2004 July 1 through 2008 June 30. For each flyby we also describe the encounter geometry, and we discuss the studies that have previously been published using the VIMS dataset. The resulting compliation of metadata provides a complementary big-picture overview of the VIMS data in the public archive, and should be a useful reference for future Titan studies.

Published
2009
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5. A multi-wavelength simultaneous study of the composition of the Halley Family Comet 8P/Tuttle

Author

Hugues Sana, Anita L. Cochran, N. Biver, Harold A. Weaver, Alain Smette, Jean Manfroid, J.-M. Zucconi, Emmanuel Jehin, J. A. Stüwe, Heike Rauer, J. Crovisier, N. Dello Russo, Hideyo Kawakita, Damien Hutsemekers, Claude Arpigny, M. Weiler, Pierre Magain, Dominique Bockelée-Morvan, Hitomi Kobayashi, Rita Schulz, Ronald J. Vervack, Institut d'Astrophysique, Géophysique et Océanographie, Université de Liège, 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), Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Applied Physics Laboratory, Johns Hopkins University, Kyoto Sangyo University, Research and Scientific Support Department, ESA-ESTEC (RSSD), European Southern Observatory (ESO), Leiden Observatory, Department of Astronomy and McDonald Observatory, University of Texas, Austin, DLR Institut für Planetenerkundung, Université de Franche-Comté (UFC), and Université Bourgogne Franche-Comté [COMUE] (UBFC)

Subjects
Physics, Very Large Telescope, spectroscopy, Infrared, comet 8P/Tuttle, Comet, Infrared spectroscopy, Astronomy, Astronomy and Astrophysics, Astrophysics, gas composition, Jupiter, Planetary science, Space and Planetary Science, Earth and Planetary Sciences (miscellaneous), comets, Spectroscopy, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Long-slit spectroscopy
Abstract

International audience; We report on simultaneous optical and infrared observations of the Halley Family comet 8P/Tuttle performed with the ESO Very Large Telescope. Such multi-wavelength and coordinated observations are a good example of what can be done to support space missions. From high resolution optical spectroscopy of the CN (0,0) 388 nm and NH2 (0,9,0) 610 nm bands using UVES at UT2 we determined 12C/13C = 90 ± 10 and 14N/15N = 150 ± 20 in CN and we derived a nuclear spin temperature of NH3 of 29 ± 1 K. These values are similar to those found in Oort-Cloud and Jupiter Family comets. From low resolution long slit spectroscopy with FORS1 at UT2 we determined the CN, C3 and C2 production rates and the parent and daughter scale lengths up to 5.2 105 km tailward. From high resolution IR spectroscopy with CRIRES at UT1 we measured simultaneously the production rates and mixing ratios of H2O, HCN, C2H2, CH4, C2H6, and CH3OH.

Published
2009
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6. Corrigendum to 'New determination of the size and bulk density of the binary Asteroid 22 Kalliope from observations of mutual eclipses' [Icarus 196 (2008) 578 600]

Author

Agnieszka Kryszczyńska, I. Verestchagina, K. A. Kettner, J.-F. Coliac, P. Wiggins, W. Romanishin, Magdalena Polińska, Mirel Birlan, Jérôme Berthier, Pascal Descamps, Joe Pollock, Frédéric Vachier, F. Marchis, M. H. Wong, D. Gorshanov, Alan W. Harris, E. M. Cooper, A. Devyatkin, Mikko Kaasalainen, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Groupe Astrométrie et Planétologie (GAP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Department of Astronomy, University of California, Department of Physics and Astronomy, Appalachian State University, Department of Mathematics and Statistics, Rolf Nevanlinna Institute, University of Helsinki, DLR Institut für Planetenerkundung, Department of Physics and Astronomy, University of Oklahoma, Wiggins Observatory, Adam Mickiewicz University in Poznań (UAM), Observatoire de la Farigourette, and Central Astronomical Observatory

Subjects
ICARUS, Physics, 010504 meteorology & atmospheric sciences, Astronomy, Binary number, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Bulk density, Space and Planetary Science, Asteroid, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract

Corrigendum to “New determination of the size and bulk density of the binary Asteroid 22 Kalliope from observations of mutual eclipses” [Icarus 196 (2008) 578–600] P. Descamps a,∗, F. Marchis a,b,j, J. Pollock c, J. Berthier a, F. Vachier a, M. Birlan a, M. Kaasalainen d, A.W. Harris e, M.H. Wong b, W.J. Romanishin f, E.M. Cooper f, K.A. Kettner f, P. Wiggins g, A. Kryszczynska h, M. Polinska h, J.-F. Coliac i, A. Devyatkin k, I. Verestchagina k, D. Gorshanov k

Published
2009
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7. Venus surface thermal emission at 1μm in VIRTIS imaging observations: Evidence for variation of crust and mantle differentiation conditions

Author

Stéphane Erard, Nils Mueller, Constantine Tsang, George Hashimoto, Giuseppe Piccioni, Pierre Drossart, Jörn Helbert, Westfälische Wilhelms-Universität Münster = University of Münster (WWU), DLR Institut für Planetenerkundung, Laboratory for Earth and Planetary Atmospheric Science, Department of Earth and Planetary Sciences, Atmospheric, Oceanic and Planetary Physics, Department of Physics, Clarendon Laboratory, University of Oxford, 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), Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), and Istituto di Astrofisica Spaziale e Fisica Cosmica (IASF-Roma)

Subjects
Atmospheric Science, Opacity, Soil Science, Venus, clouds, Volcanism, tessera highlands, Aquatic Science, Oceanography, Mantle (geology), vulcanism, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), Emissivity, Earth-Surface Processes, Water Science and Technology, Venus Express, geography, geography.geographical_feature_category, Ecology, biology, scattering, temperature, Paleontology, Forestry, Lapse rate, Crust, Geophysics, VIRTIS, biology.organism_classification, Volcano, Space and Planetary Science, emissivity, atmosphere, Visible and Infrared Thermal Imaging Spectrometer, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], absorption, Geology
Abstract

International audience; The Venus Express spacecraft images the nightside thermal emissions using the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS). At 1.02, 1.10, and 1.18 mum, thermal emission from the surface is observed. The signal is attenuated by scattering and absorption in the dense atmosphere. The measured flux at the top of the atmosphere is positively correlated with surface temperature and surface emissivity. The surface temperature of Venus is relatively well constrained as being mainly a function of altitude with a gradient lesser or equal to the adiabatic lapse rate. This study examines the correlation of VIRTIS images showing a signal of the surface at 1.02 mum with viewing geometry, stray sunlight, cloud opacity, and topography and applies semiempirical relations to remove their influence. The remaining contrast can be either ascribed to surface emissivity or unexpected temperature variations. Temperature variations due to active volcanism are unlikely to be persistent over the time of observations; therefore, the mosaic of all processed images is here interpreted in terms of surface emissivity variation. The emissivity variation found is correlated with geomorphological features established from Magellan synthetic aperture radar images. It is generally lower at tessera terrain. Some, but not all, volcanic edifices show increased emissivity. Large lava flows in the Lada terra-Lavinia planitia region also show an increased thermal emission. This might indicate a more felsic surface composition of tessera highlands and large-scale extrusive volcanism of ultramafic composition.

Published
2008
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8. Determination of the light curve of the Rosetta target Asteroid (2867) Steins by the OSIRIS cameras onboard Rosetta

Author

Michael F. A'Hearn, Cesare Barbieri, Michael Kueppers, P. J. Gutiérrez, Stephen C. Lowry, Olivier Groussin, Philippe Lamy, S. F. Hviid, S. Fornasier, H. U. Keller, M. A. Barucci, Stefano Mottola, 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), Beaussier, Catherine, Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, DLR Institut für Planetenerkundung, Queen's University [Belfast] (QUB), Department of Astronomy, University of Maryland, Università degli Studi di Padova = University of Padua (Unipd), Université Paris Cité (UPCité), 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), Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), and Instituto de Astrofisica de Andalucia, CSIC (IAA)

Subjects
asteroids, Rotation period, photometry, 2867 Steins, FOS: Physical sciences, Context (language use), Astrophysics, minor planets, main belt asteroids, Rotation, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Apparent magnitude, Phase angle (astronomy), Orientation (geometry), Rosetta, OSIRIS, Physics, photometric [Techniques], Astrophysics (astro-ph), Astronomy and Astrophysics, Light curve, Minor planets, asteroids, Space and Planetary Science, Asteroid, [PHYS.ASTR.CO] Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Techniques: photometric
Abstract

7 pp.-- Article published by EDP Sciences and available at http://www.aanda.org or http://dx.doi.org/10.1051/0004-6361:20066694.-- Table 2 is only available in electronic form at http://www.aanda.org., [Context] In 2004 asteroid (2867) Steins has been selected as a flyby target for the Rosetta mission. Determination of its spin period and the orientation of its rotation axis are essential for optimization of the flyby planning., [Aims] Measurement of the rotation period and light curve of asteroid (2867) Steins at a phase angle larger than achievable from ground based observations, providing a high quality data set to contribute to the determination of the orientation of the spin axis and of the pole direction., [Methods] On March 11, 2006, asteroid (2867) Steins was observed continuously for 24 h with the scientific camera system OSIRIS onboard Rosetta. The phase angle was 41.7 degrees, larger than the maximum phase angle of 30 degrees when Steins is observed from Earth. A total of 238 images, covering four rotation periods without interruption, were acquired., [Results] The light curve of (2867) Steins is double peaked with an amplitude of ≈0.23 mag. The rotation period is 6.052 ± 0.007 h. The continuous observations over four rotation periods exclude the possibility of period ambiguities. There is no indication of deviation from a principal axis rotation state. Assuming a slope parameter of G = 0.15, the absolute visual magnitude of Steins is 13.05 ± 0.03., The OSIRIS imaging system on board Rosetta is managed by the Max-Planck-Intitute for Solar System Research in Katlenburg-Lindau (Germany), thanks to an International collaboration between Germany, France, Italy, Spain, and Sweden. The support of the national funding agencies DLR, CNES, ASI, MEC, and SNSB is gratefully acknowledged. We acknowledge the work of the Rosetta Science Operations Centre at ESA/ESTEC and of the Rosetta Mission Operations Centre at ESA/ESOC who made these observations possible on short notation and operated the spacecraft. S.C.L. acknowledges support from the Leverhulme Trust. This research made use of JPL’s online ephemeris generator (HORIZONS).

Published
2006
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9. Comparative blind test of five planetary transit detection algorithms on realistic synthetic light curves

Author

Pierre Barge, Holger Voss, Frederic Pont, C. Moutou, P. Guterman, Suzanne Aigrain, R. Cautain, Antonino F. Lanza, D. Blouin, M. Auvergne, V. Guis, D. Queloz, Heike Rauer, Anders Erikson, Mike Irwin, Shay Zucker, 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), Observatoire Astronomique de l'Université de Genève, Institute of Astronomy, University of Cambridge (IoA), 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), DLR Institut für Planetenerkundung, Gemplus, and INAF-Osservatorio Astrofisico di Catania (INAF-OACt)

Subjects
Physics, Astronomy, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Planetary system, Light curve, Orbital period, Exoplanet, Stars, planetary systems -- methods: data analysis -- techniques: photometric -- methods: observational, Space and Planetary Science, Planet, Binary star, Astrophysics::Solar and Stellar Astrophysics, Transit (astronomy), Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Algorithm
Abstract

Because photometric surveys of exoplanet transits are very promising sources of future discoveries, many algorithms are being developed to detect transit signals in stellar light curves. This paper compares such algorithms for the next generation of space-based transit detection surveys like CoRoT, Kepler, and Eddington, Five independent analyses of a thousand synthetic light curves are presented. The light curves were produced with an end-to-end instrument simulator and include stellar microvariability and a varied sample of stellar and planetary transits diluted within a much larger set of light curves. The results show that different algorithms perform quite differently, with varying degrees of success in detecting real transits and avoiding false positives. We also find that the detection algorithm alone does not make all the difference, as the way the light curves are filtered and detrended beforehand also has a strong impact on the detection limit and on the false alarm rate. The microvariability of sun-like stars is a limiting factor only in extreme cases, when the fluctuation amplitudes are large and the star is faint. In the majority of cases it does not prevent detection of planetary transits. The most sensitive analysis is performed with periodic box-shaped detection filters. False positives are method-dependent, which should allow reduction of their detection rate in real surveys. Background eclipsing binaries are wrongly identified as planetary transits in most cases, a result which confirms that contamination by background stars is the main limiting factor. With parameters simulating the CoRoT mission, our detection test indicates that the smallest detectable planet radius is on the order of 2 Earth radii for a 10-day orbital period planet around a KO dwarf. © ESO 2005.

Published
2005
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