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9 results on '"Gregorio, J"'

1. VizieR Online Data Catalog: KOI-1257 photometric and velocimetric data (Santerne+, 2014)

Author

Santerne, A., Hebrard, G., Deleuil, M., Havel, M., Correia, A. C. M., Almenara, J.-M., Alonso, R., Arnold, L., Barros, S. C. C., Behrend, R., Bernasconi, L., Boisse, I., Bonomo, A. S., Bouchy, F., Bruno, G., Damiani, C., Diaz, R. F., Gravallon, D., Guillot, T., Labrevoir, O., Montagnier, G., Moutou, C., Rinner, C., Santos, N. C., Abe, L., Audejean, M., Bendjoya, P., Gillier, C., Gregorio, J., Martinez, P., Michelet, J., Montaigut, R., Poncy, R., Rivet, J.-P., Rousseau, G., Roy, R., Suarez, O., Vanhuysse, M., Verilhac, D., and bibliotheque, la.

Subjects
Radial velocities, Photometry: CCD, Line Profiles, [PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph], Stars: double and multiple
Abstract

In this paper we report a new transiting warm giant planet: KOI-1257b. It was first detected in photometry as a planet-candidate by the Kepler space telescope and then validated thanks to a radial velocity follow-up with the SOPHIE spectrograph. It orbits its host star with a period of 86.647661d+/-3s and a high eccentricity of 0.772+/-0.045. The planet transits the main star of a metal-rich, relatively old binary system with stars of mass of 0.99+/-0.05M⊙ and 0.70+/-0.07M⊙ for the primary and secondary, respectively. This binary system is constrained thanks to a self-consistent modelling of the Kepler transit light curve, the SOPHIE radial velocities, line bisector and full-width half maximum (FWHM) variations, and the spectral energy distribution. However, future observations are needed to confirm it. The PASTIS fully-Bayesian software was used to validate the nature of the planet and to determine which star of the binary system is the transit host. By accounting for the dilution from the binary both in photometry and in radial velocity, we find that the planet has a mass of 1.45+/-0.35Mjup, and a radius of 0.94+/-0.12Rjup, and thus a bulk density of 2.1+/-1.2g/cm3. The planet has an equilibrium temperature of 511+/-50K, making it one of the few known members of the warm-Jupiter population. The HARPS-N spectrograph was also used to observe a transit of KOI-1257b, simultaneously with a joint amateur and professional photometric follow-up, with the aim of constraining the orbital obliquity of the planet. However, the Rossiter-McLaughlin effect was not clearly detected, resulting in poor constraints on the orbital obliquity of the planet. (3 data files).

Published
2014

2. A new approach for estimating Titan's electron conductivity based on data from Relaxation Probe sensors on the Huygens Experiment

Author

Michel Hamelin, M. J. Núñez, M. Fulchignoni, Réjean Grard, R. Godard, V. Brown, Konrad Schwingenschuh, Peter Falkner, Roland Trautner, Irmgard Jernej, Francesca Ferri, J. M. Jeronimo, Gregorio J. Molina-Cuberos, Rafael Rodrigo, Fernando Simões, C. Groth, Nada Ibrahim, José Juan López-Moreno, Departamento de Física [Murcia], Universidad de Murcia, Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Department of Mathematics and Computer Science [Kingston], Royal Military College of Canada, 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), Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), 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), NASA Goddard Space Flight Center (GSFC), Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Agence Spatiale Européenne = European Space Agency (ESA), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Università degli Studi di Padova = University of Padua (Unipd), Institute for Aerospace Studies (UTIAS), University of Toronto, 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 Agency (ESA)-European Space Agency (ESA), European Space Agency (ESA), and Universita degli Studi di Padova

Subjects
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], Electron, Conductivity, 7. Clean energy, 01 natural sciences, symbols.namesake, Optics, Electrical resistivity and conductivity, 0103 physical sciences, Relaxation Probe, Atmosphere of Titan, 010303 astronomy & astrophysics, Debye length, 0105 earth and related environmental sciences, Physics, Laplace transform, business.industry, Atmospheric ElectronConductivity, Space Instrumentation, Astronomy and Astrophysics, Computational physics, Space and Planetary Science, symbols, Poisson's equation, Titan (rocket family), business, Titan
Abstract

International audience; The Huygens Probe measured the electrical conductivity of Titan atmosphere from about 140 km down to the surface, employing relaxation and mutual impedance techniques. Previous analyses have shown some differences on the conductivity measurements obtained with two independent sensors - Relaxation Probe (RP) and Mutual Impedance Probe (MIP). A 20-fold maximum discrepancy occurred around the conductivity peak at 60-70 km. To understand the nature of such discrepancy, we reassess the RP data by taking into account a geometrical factor related to the electrode finite size and the Debye length of the ionized medium. The present analysis implies replacing the standard Laplace field distribution by a more elaborated model considering the Poisson equation and the resistance between the RP electrodes and the medium. Although a complete understanding of the conductivity profile is still missing, this work brings RP and MIP data to a much better agreement. The conductivity maximum difference derived from the two sensors is now lower a factor of 2. This reassessment is also useful for future instruments and missions.

Published
2010
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3. The Schumann Resonance: a Tool for Exploring the Atmospheric Environment and the Subsurface of the Planets and their Satellites

Author

Konrad Schwingenschuh, J. J. Lopez-Moreno, Jean-Pierre Lebreton, Réjean Grard, Gregorio J. Molina-Cuberos, Michel Hamelin, C. Beghin, Fernando Simões, Jean-Jacques Berthelier, Tetsuya Tokano, Centre d'étude des environnements terrestre et planétaires (CETP), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA)-European Space Agency (ESA), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Austrian Academy of Sciences (OeAW), 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, 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), Departamento de Física [Murcia], Universidad de Murcia, Institut für Geophysik und Meteorologie [Köln], and Universität zu Köln

Subjects
Atmospheres, 010504 meteorology & atmospheric sciences, Electromagnetic environment, Planets, 01 natural sciences, Electromagnetic radiation, Lightning, Physics::Geophysics, Optics, 0103 physical sciences, Extremely low frequency, structure, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Schumann resonances, business.industry, Interiors, Astronomy and Astrophysics, Geophysics, Atmosphere of Earth, Ionospheres, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Reflection (physics), Ionosphere, business
Abstract

International audience; The propagation of extremely low frequency (ELF) electromagnetic waves and resonance phenomena in the Earth atmosphere has been extensively studied, in relation with ionospheric dynamics, and thunderstorm and lightning activities. A similar investigation can be performed for any other planet and satellite environment, provided this body is wrapped into an ionosphere. There are, however, important differences between Earth and other bodies, regarding the surface conductivity, the atmospheric electron density, the ionospheric cavity geometry, and the sources of electromagnetic energy. In a first approximation, the size of the cavity defines the range of the resonance frequency; the electron density profile, up to the upper atmospheric boundary, controls the wave attenuation; the nature of the electromagnetic sources influences the field distribution in the cavity; and the body surface conductivity, which gives the reflection and transmission coefficients, indicates to what extent the subsurface can be explored. The knowledge of the frequencies and attenuation rates of the principal eigenmodes provides unique information about the electric properties of the cavity. Instruments capable of monitoring the electromagnetic environment in the ELF range are, therefore, valuable payload elements on balloons, descent probes and landers. We develop models for selected inner planets, gaseous giants and their satellites, and review the propagation process of ELF electromagnetic waves in their atmospheric cavities, with a particular emphasis on the application of the Schumann resonance observation to subsurface studies. The instrumentation suitable for monitoring the electromagnetic environment in geophysical cavities is briefly addressed.

Published
2008
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4. Electron conductivity and density profiles derived from the mutual impedance probe measurements performed during the descent of Huygens through the atmosphere of Titan

Author

Francesca Ferri, Fernando Simões, C. Beghin, Tetsuya Tokano, Gregorio J. Molina-Cuberos, Michel Chabassière, Marcello Fulchignoni, Rafael Rodrigo, Konrad Schwingenschuh, V. Brown, Peter Falkner, Irmgard Jernej, Michel Hamelin, J. J. López-Moreno, J. M. Jeronimo, Jean-Jacques Berthelier, R. Grard, R. Trautner, Centre d'étude des environnements terrestre et planétaires (CETP), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique et chimie de l'environnement (LPCE), Université d'Orléans (UO)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA)-European Space Agency (ESA), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, 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), Departamento de Física [Murcia], Universidad de Murcia, Institut für Geophysik und Meteorologie [Köln], Universität zu Köln, Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Università degli Studi di Padova = University of Padua (Unipd), and Universität zu Köln = University of Cologne

Subjects
Permittivity, Electron density, 010504 meteorology & atmospheric sciences, Atmospheric conductivity, Electron, 01 natural sciences, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], symbols.namesake, Optics, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], Ionization, 0103 physical sciences, Altimeter, Atmosphere of Titan, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Huygens probe, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], business.industry, Astronomy and Astrophysics, Atmospheric electricity, Space and Planetary Science, symbols, Titan (rocket family), business, Titan
Abstract

During the descent of the Huygens probe through the atmosphere of Titan, on January 14th, 2005, the permittivity, waves and altimetry (PWA) subsystem, a component of the Huygens atmospheric structure instrument (HASI), detected an ionized layer at altitudes around 63 km with two different instruments, the relaxation probe (RP) and the mutual impedance probe (MIP). A very detailed analysis of both data sets is required, in order to correct for environmental effects and compare the two independent estimates of the electrical conductivity. The present work is dedicated to the MIP data analysis. New laboratory tests have been performed to validate or improve the available calibration results. Temperature effects have been included and numerical models of the MIP sensors and electric circuitry have been developed to take into account the proximity of the Huygens probe body. The effect of the vertical motion of the vessel in the ionized atmosphere is estimated in both analytical and numerical ways. The peculiar performance of the instrument in the altitude range 100–140 km is scrutinized. The existence of a prominent ionized layer, and of enhancements in the conductivity and electron density profiles at 63 km, are discussed in the light of previous theoretical predictions.

Published
2007
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5. Conductivity and electron density in Titan's atmosphere as deduced from Mutual Impedance measurements by the PWA-HASI instrument on HUYGENS

Author

Hamelin, Michel, Béghin, Christian, Brown, V. J., Grard, Rejean, Jernej, I., López-Moreno, José J., Schwingenschuh, K., Simões, Fernando, Trautner, Roland, Molina-Cuberos, Gregorio J., Berthelier, Jean-Jacques, Chabassière, M., Falkner, P., Ferri, Francesca, Fulchignoni, Marcello, Hofe, R., Jeronimo, J. J., Lara, Luisa M., Rodrigo, Rafael, Svedhem, Håkan, Tokano, Tetsuya, Centre d'étude des environnements terrestre et planétaires (CETP), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique et chimie de l'environnement (LPCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Institut für Weltraumforschung = Space Research institute [Graz] (IWF), Osterreichische Akademie der Wissenschaften (ÖAW), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Università degli Studi di Padova = University of Padua (Unipd), 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 Universität zu Köln = University of Cologne

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience; During the descent of the HUYGENS Probe through the atmosphere of Titan, January 14th, 2005, the permittivity, Waves and Altimetry (PWA), a subsystem of the HUYGENS Atmospheric Structure Instrument (HASI) detected an ionized layer around the altitude of 60 km with two different instruments, the Relaxation Probe (RP) and the Mutual Impedance Probe (MIP). For both instruments a more detailed data analysis, including unforeseen environmental effects, was necessary to reach precise quantitative estimations of the electrical conductivity. The present work is dedicated to the MIP data analysis. New laboratory tests have been performed to correct and validate the calibration data. Temperature effects have been included and two different numerical models of MIP electrodes and circuits in the HUYGENS body environment have been used. The effect of motion of HUYGENS in the ionized atmosphere that was neglected in the first analysis is revealed and analytical estimations of this effect allow to derive more accurate values of the conductivity. The final results are discussed, compared to the RP results and electron density profiles are deduced showing more precisely the lower ionized layer.

Published
2006

6. Electric Conductivity And Waves In The Atmosphere Of Titan From The Pwa-hasi Instrument On The Huygens Probe

Author

Hamelin, Michel, Brown, V. J., Béghin, Christian, Chabassière, M., Falkner, P., Ferri, Francesca, Fulchignoni, Marcello, Grard, Rejean, Hofe, R., Jernej, I., Lara, Luisa M., López-Moreno, José J., Molina-Cuberos, Gregorio J., Rodrigo, Rafael, Schwingenschuh, K., Simões, Fernando, Trautner, Roland, 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, and 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)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience

Published
2006

7. Electric properties and related physical characteristics of the atmosphere and surface of Titan

Author

Fernando Simões, Jean-Jacques Berthelier, Irmgard Jernej, Michel Hamelin, Tetsuya Tokano, R. Grard, V. Brown, J. M. Jeronimo, M. Chabassiere, Peter Falkner, Francesca Ferri, Håkan Svedhem, Marcello Fulchignoni, J. J. López-Moreno, Rafael Rodrigo, R. Trautner, C. Beghin, Konrad Schwingenschuh, L. M. Lara, Gregorio J. Molina-Cuberos, Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA)-European Space Agency (ESA), Centre d'étude des environnements terrestre et planétaires (CETP), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-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), Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Departamento de Física [Murcia], Universidad de Murcia, Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, 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 de physique et chimie de l'environnement (LPCE), Université d'Orléans (UO)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut für Geophysik und Meteorologie [Köln], Universität zu Köln, Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Università degli Studi di Padova = University of Padua (Unipd), Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), and Universität zu Köln = University of Cologne

Subjects
Permittivity, Materials science, 010504 meteorology & atmospheric sciences, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Relative permittivity, Astronomy and Astrophysics, Geophysics, 01 natural sciences, Computational physics, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], symbols.namesake, 13. Climate action, Space and Planetary Science, Electrical resistivity and conductivity, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], Electric field, 0103 physical sciences, symbols, Atmospheric electricity, Atmosphere of Titan, Ionosphere, Titan (rocket family), 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract

The permittivity, waves and altimetry (PWA) instrument was designed for the investigation of the electric properties and other related physical characteristics of the atmosphere of Titan, from an altitude around 140 km down to the surface. PWA carried sensors to measure the atmospheric conductivity, and record electromagnetic and acoustic waves up to frequencies of 11.5 and 6.7 kHz, respectively. PWA also measured the relief roughness during the descent and the permittivity of the surface after touchdown. The measurements and the results of the preliminary analysis are presented. An ionized layer is detected at altitudes above 50 km, using two independent techniques, and the presence of free electrons in the upper atmosphere is confirmed. An electric signal at around 36 Hz is observed throughout the descent, but it is not yet confirmed that this emission is unambiguously related to a resonance of the ionospheric cavity. The relative dielectric constant of Titan's surface material is nearly 2 and the electric conductivity 4×10−10 S m−1. The electric properties of the surface seem to evolve after touch-down, possibly due to a local warming of the landing site by the Huygens Probe body.

Published
2006
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8. Preliminary Analysis of the Extremely Low Frequency Signals Detected With the PWA-HASI Instrument During the Descent of the Huygens Probe Through the Atmosphere of Titan

Author

Simões, Fernando, Brown, V., Chabassière, M., Falkner, P., Ferri, Francesca, Fulchignoni, Marcello, Grard, Rejean, Hamelin, Michel, Hofe, R., Jernej, I., Lara, Luisa M., López-Moreno, José J., Molina-Cuberos, Gregorio J., Rodrigo, Rafael, Schwingenschuh, K., Trautner, Roland, 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, and 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)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience

Published
2005

9. Measurement of the Electronic and Ionic Conductivities With a Relaxation Probe in the Atmosphere of Titan

Author

Grard, Rejean, Brown, V., Chabassière, M., Falkner, P., Ferri, Francesca, Fulchignoni, Marcello, Hamelin, Michel, Hofe, R., Jernej, I., Lara, Luisa M., López-Moreno, José J., Molina-Cuberos, Gregorio J., Rodrigo, Rafael, Schwingenschuh, K., Simões, Fernando, Trautner, Roland, 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, and 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)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience

Published
2005

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