References of "Stiepen, Arnaud"
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See detailUn demi-siècle d''exploration de la planète Mars
Stiepen, Arnaud ULg

Conference given outside the academic context (2016)

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See detailLa tête en l'air, les pieds sur Terre
Stiepen, Arnaud ULg

Conference given outside the academic context (2016)

Detailed reference viewed: 14 (3 ULg)
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See detailNitric Oxide nightglow as a tracer of inter-hemispheric circulation: Detailed comparison with the LMD-GCM
Stiepen, Arnaud ULg; IUVS team; Gonzales-Galindo et al

Conference (2016, September)

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See detailExoMars : L’Europe en route vers Mars !
Stiepen, Arnaud ULg

Article for general public (2016)

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See detailL'épopée Planet Nine. Doit-on réécrire les manuels scolaires d'astronomie?
Stiepen, Arnaud ULg

Article for general public (2016)

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See detailA quoi sert un astrophysicien?
Stiepen, Arnaud ULg

Conference given outside the academic context (2016)

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See detailAux astres, citoyens! Oufti! Liège dans l'espace!
Stiepen, Arnaud ULg

Article for general public (2016)

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See detailSeasonal variability of the Nitric Oxide nightglow observed by IUVS/MAVEN
Stiepen, Arnaud ULg; IUVS team

Scientific conference (2016, May 19)

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See detailGlobal simulation of UV atmospheric emissions on Mars
González-Galindo; López-Valverde; Forget et al

Poster (2016, April)

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See detailMAVEN Imaging UV Spectrograph Results on the Mars Atmosphere and Atmospheric Escape
Chaffin; Schneider; McClintock et al

Conference (2016, April)

Detailed reference viewed: 13 (1 ULg)
See detailLa Guerre des Etoiles sous la loupe d'un astrophysicien
Stiepen, Arnaud ULg

Article for general public (2016)

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See detailAux astres, citoyens! Planet Nine
Stiepen, Arnaud ULg

Article for general public (2016)

Detailed reference viewed: 13 (2 ULg)
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See detailDeciphering Mars lower atmosphere: Nitric Oxide nightglow seasonal variations as observed by IUVS
Stiepen, Arnaud ULg

Scientific conference (2016, February 02)

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See detailNew and updated convex shape models of asteroids based on optical data from a large collaboration network
Hanuš, J.; Ďurech, J.; Oszkiewicz, D. A. et al

in Astronomy & Astrophysics (2016), 586

Asteroid modeling efforts in the last decade resulted in a comprehensive dataset of almost 400 convex shape models and their rotation states. This amount already provided a deep insight into physical ... [more ▼]

Asteroid modeling efforts in the last decade resulted in a comprehensive dataset of almost 400 convex shape models and their rotation states. This amount already provided a deep insight into physical properties of main-belt asteroids or large collisional families. We aim to increase the number of asteroid shape models and rotation states. Such results are an important input for various further studies such as analysis of asteroid physical properties in different populations, including smaller collisional families, thermophysical modeling, and scaling shape models by disk-resolved images, or stellar occultation data. This provides, in combination with known masses, bulk density estimates, but constrains also theoretical collisional and evolutional models of the Solar System. We use all available disk-integrated optical data (i.e., classical dense-in-time photometry obtained from public databases and through a large collaboration network as well as sparse-in-time individual measurements from a few sky surveys) as an input for the convex inversion method, and derive 3D shape models of asteroids, together with their rotation periods and orientations of rotation axes. The key ingredient is the support of more that one hundred observers who submit their optical data to publicly available databases. We present updated shape models for 36 asteroids, for which mass estimates are currently available in the literature or their masses will be most likely determined from their gravitational influence on smaller bodies, which orbital deflection will be observed by the ESA Gaia astrometric mission. This was achieved by using additional optical data from recent apparitions for the shape optimization. Moreover, we also present new shape model determinations for 250 asteroids, including 13 Hungarias and 3 near-Earth asteroids. [less ▲]

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See detail50 ans d'exploration de la planète Mars
Stiepen, Arnaud ULg

Conference given outside the academic context (2016)

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See detailNotre Système Solaire
Stiepen, Arnaud ULg

Conference given outside the academic context (2016)

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See detailLe Système Solaire
Stiepen, Arnaud ULg

Conference given outside the academic context (2016)

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Peer Reviewed
See detailSPICAM observations and modeling of Mars aurorae
Soret, Lauriane ULg; Gérard, Jean-Claude ULg; Libert, Ludivine ULg et al

in Icarus (2016), 264

Martian aurorae have been detected with the SPICAM instrument on board Mars Express both in the nadir and the limb viewing modes. In this study, we focus on three limb observations to determine both the ... [more ▼]

Martian aurorae have been detected with the SPICAM instrument on board Mars Express both in the nadir and the limb viewing modes. In this study, we focus on three limb observations to determine both the altitudes and the intensities of the auroral emissions. The CO (a3P–X1R) Cameron bands between 190 and 270 nm, the CO Fourth Positive system (CO 4P) between 135 and 170 nm, the CO2+ doublet at 289 nm, the OI at 297.2 nm and the 130.4 nm OI triplet emissions have been identified in the spectra and in the time variations of the signals. The intensities of these auroral emissions have been quantified and the altitude of the strongest emission of the CO Cameron bands has been estimated to be 137 ± 27 km. The locations of these auroral events have also been determined and correspond to the statistical boundary of open-closed magnetic field lines, in cusp-like structures. The observed altitudes of the auroral emissions are reproduced by a Monte-Carlo model of electron transport in the Martian thermosphere for mono-energetic electrons between 40 and 200 eV. No correlation between electron fluxes measured in the upper thermosphere and nadir auroral intensity has been found. Here, we simulate auroral emissions observed both at the limb and at the nadir using electron energy spectra simultaneously measured with the ASPERA-3/ELS instrument. The simulated altitudes are in very good agreement with the observations. We find that predicted vertically integrated intensities for the various auroral emissions are overestimated, probably as a consequence of the inclination and curvature of the magnetic field line threading the aurora. However, the relative brightness of the CO and CO2+ emissions is in good agreement with the observations. [less ▲]

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See detailIndiana Jones sur Mars
Stiepen, Arnaud ULg

Scientific conference (2015, December 17)

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See detailFirst Analysis of Martian Nightglow Seasonal Variations Observed by MAVEN's Imaging Ultraviolet Spectrograph
Stiepen, Arnaud ULg; IUVS team

Poster (2015, December 15)

We report results from a study of nitric oxide nightglow over the northern hemisphere of Mars during winter and southern hemisphere during equinox. We present observations of the nitric oxide δ and γ band ... [more ▼]

We report results from a study of nitric oxide nightglow over the northern hemisphere of Mars during winter and southern hemisphere during equinox. We present observations of the nitric oxide δ and γ band emissions between 190 and 270 nm by the Imaging UltraViolet Spectrograph on the MAVEN spacecraft. The emission reveals recombination of N and O atoms dissociated on the dayside of Mars, and is known to trace upper atmosphere hemispheric circulation patterns. We extend previous studies to higher latitudes, finding brighter emissions closer to the poles as predicted from global circulation models. Statistically significant variability suggests variation of the fluxes of N and O carried from the dayside thermosphere, as well as possible variations of the wind pattern in the nightside thermosphere and mesosphere. [less ▲]

Detailed reference viewed: 12 (0 ULg)