Audrey Thirouin
A5066934578- Astro and Planetary Science
- Planetary Science and Exploration
- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Space Exploration and Technology
- Astronomical Observations and Instrumentation
- High-pressure geophysics and materials
- Isotope Analysis in Ecology
- Geomagnetism and Paleomagnetism Studies
- Astronomy and Astrophysical Research
- Spacecraft Design and Technology
- Space Satellite Systems and Control
- Gamma-ray bursts and supernovae
- Geology and Paleoclimatology Research
- Geological and Geochemical Analysis
- Solar and Space Plasma Dynamics
- Atmospheric Ozone and Climate
- Spacecraft and Cryogenic Technologies
- Calibration and Measurement Techniques
- Methane Hydrates and Related Phenomena
- Geophysics and Gravity Measurements
- Adaptive optics and wavefront sensing
- Atomic and Subatomic Physics Research
- Ionosphere and magnetosphere dynamics
- Marine and environmental studies
Lowell Observatory
2015-2024
Instituto de Astrofísica de Andalucía
2009-2019
Laboratoire d’Astrophysique de Marseille
2019
Aix-Marseille Université
2019
Centre National de la Recherche Scientifique
2019
Consejo Superior de Investigaciones Científicas
2009-2017
University of Arizona
2016
Goddard Space Flight Center
2014
Abstract The Outer Solar System Origins Survey (OSSOS), a wide-field imaging program in 2013–2017 with the Canada–France–Hawaii Telescope, surveyed 155 deg 2 of sky to depths m r = 24.1–25.2. We present 838 outer solar system discoveries that are entirely free ephemeris bias. This increases inventory trans-Neptunian objects (TNOs) accurately known orbits by nearly 50%. Each minor planet has 20–60 Gaia /Pan-STARRS-calibrated astrometric measurements made over 2–5 oppositions, which allows...
The Vera C. Rubin Observatory is expected to start the Legacy Survey of Space and Time (LSST) in early mid-2025. This multi-band wide-field synoptic survey will transform our view solar system, with discovery monitoring over 5 million small bodies.The final strategy chosen for LSST has direct implications on discoverability characterization system minor planets passing interstellar objects. Creating an inventory one four main science drivers. observing cadence a complex optimization problem...
We present results derived from the first multi-chord stellar occultations by transneptunian object (50000) Quaoar, observed on 2011 May 4 and 2012 February 17, a single-chord occultation October 15. If timing of five chords obtained in were correct, then Quaoar would possess topographic features (crater or mountain) that be too large for body this mass. An alternative model consists applying time shifts to some account possible errors. Satisfactory elliptical fits are possible, yielding an...
We propose that several short duration events observed in past stellar occultations by Chiron were produced rings material. From a reanalysis of the occultation data literature we determined two possible orientations pole Chiron's rings, with ecliptic coordinates l=(352+/-10) deg, b=(37+/-10) deg or l=(144+/-10) b=(24+/-10) . The mean radius is (324 +/- 10) km. One can use rotational lightcurve amplitude at different epochs to distinguish between solutions for pole. Both imply lower 2013...
Abstract We performed photometric observations of the binary near-Earth asteroid (65803) Didymos in support Double Asteroid Redirection Test (DART) mission that will test Kinetic Impactor technology for diverting dangerous asteroids. It hit secondary, called Dimorphos, on 2022 September 26. observed with 11 telescopes diameters from 3.5 to 10.4 m during four apparitions 2015–2021, obtaining data rms residuals 0.006 0.030 mag. analyzed light-curve and decomposed them into primary rotational...
Abstract On 2022 September 26, the Double Asteroid Redirection Test (DART) spacecraft impacted Dimorphos, satellite of binary near-Earth asteroid (65803) Didymos. This demonstrated efficacy a kinetic impactor for planetary defense by changing orbital period Dimorphos 33 minutes. Measuring change relied heavily on coordinated campaign lightcurve photometry designed to detect mutual events (occultations and eclipses) as direct probe satellite’s period. A total 28 telescopes contributed 224...
Abstract The study of small (<300 m) near-Earth objects (NEOs) is important because they are more closely related than larger to the precursors meteorites that fall on Earth. Collisions these bodies with Earth also frequent. Although such collisions cannot produce massive extinction events, can still significant local damage. Here we present results a photometric and spectroscopic survey NEOs include near-infrared spectra 84 mean diameter 126 m data 59 87 m. We found S-complex asteroids...
Abstract We report the detection of water vapor associated with main-belt comet 358P/PANSTARRS on UT 2024 January 8–9 using NIRSPEC instrument board JWST. derive a production rate <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>Q</mml:mi> </mml:mrow> <mml:mi mathvariant="normal">H</mml:mi> <mml:mn>2</mml:mn> </mml:msub> mathvariant="normal">O</mml:mi> <mml:mo>=</mml:mo> <mml:mo stretchy="false">(</mml:mo> <mml:mn>5.0</mml:mn>...
We present results of 6 years observations, reduced and analyzed with the same tools in a systematic way. report completely new data for 15 objects, 5 objects we analysis previously published plus additional 9 already published. Lightcurves, possible rotation periods photometric amplitudes are reported all them. The variability is smaller than thought: mean amplitude our sample 0.1mag only around 15% has larger 0.15mag. thought seems to be bias previous observations. find very weak trend...
Over one thousand objects have so far been discovered orbiting beyond Neptune. These trans-Neptunian (TNOs) represent the primitive remnants of planetesimal disk from which planets formed and are perhaps analogous to unseen dust parent-bodies in debris disks observed around other main-sequence stars. The dynamical physical properties these bodies provide unique important constraints on formation evolution models Solar System. While architecture this region (also known as Kuiper Belt) is...
We present Herschel PACS photometry of 18 Plutinos and determine sizes albedos for these objects using thermal modeling. analyze our results correlations, draw conclusions on the Plutino size distribution, compare to earlier results. Flux densities are derived from mini scan-maps specialized data reduction methods. In order improve quality results, we combine with existing Spitzer MIPS where possible, refine absolute magnitudes targets. The physical characterization sample is done a model....
We analyze two multi-chord stellar occultations by Pluto observed on July 18th, 2012 and May 4th, 2013, monitored respectively from five six sites. They provide a total of fifteen light-curves, twelve them being used for simultaneous fit that uses unique temperature profile, assuming clear (no-haze) pure N_2 atmosphere, but allowing possible pressure variation between the dates. find solution fits satisfactorily (i.e. within noise level) all providing atmospheric constraints ~1,190 km...
Abstract We report the cometary activity of Centaur 2023 RS 61 (RS61) evident in our UT 2025 January 2 observations with Lowell Discovery Telescope, showing a coma and ∼5 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover accent="true"> <mml:mrow> <mml:mi>.</mml:mi> </mml:mrow> <mml:mi>″</mml:mi> </mml:mover> </mml:math> 9-long tail. The archival from Pan-STARRS1 survey reveal two previously unnoticed episodes 2017 2023, suggesting SR61 could be rare...
<i>Aims. <i/>We compile and analyze an extended database of light curve parameters scattered in the literature to search for correlations study physical properties, including internal structure constraints.<i>Methods. a vast by obtaining mean rotational properties entire sample, determining spin frequency distribution comparing those data with simple model based on hydrostatic equilibrium.<i>Results. <i/>For rotation periods, value obtained is 6.95 h whole 6.88 Trans-neptunian objects (TNOs)...
We present several lines of evidence, based on different kinds observations, and we conclude that it is likely rotational fission has occurred for a fraction the known trans-Neptunian objects (TNOs). It also number binary systems have formed from process in belt. show Haumea is, potentially, an example object suffered fission. Its current fast spin would be slight evolution primordial spin, rather than result catastrophic collision. This because percentage rotating faster 4 h not small...
We present results for the short-term variability of binary trans-Neptunian objects (BTNOs). performed CCD photometric observations using 3.58 m Telescopio Nazionale Galileo (TNG), 1.5 Sierra Nevada Observatory (OSN) telescope, and 1.23 Centro Astronómico Hispano Alemán (CAHA) telescope at Calar Alto Observatory. based on five years report six BTNOs. Our sample contains three classical objects: (174567) 2003 MW12, or Varda, (120347) 2004 SB60, Salacia, 2002 VT130; one detached disk object:...
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 with semi axes $(470 \pm 20) \times (383 10) (245 8)$~km % axis ratios $b/a= 0.82...
Abstract The Mission Accessible Near-Earth Object Survey (MANOS) aims to observe and characterize small (mean absolute magnitude H ∼ 25 mag) Objects (NEOs) that are accessible by spacecraft Δ v 5.7 km s −1 ) make close approaches with the Earth Minimum Orbital Intersection Distance MOID 0.03 au). We present here first results of MANOS visible spectroscopic survey. spectra were obtained from August 2013 March 2018 at Lowell Observatory’s Discovery Channel 4.3 m telescope, both Gemini North...