G. Chauvin
A5070230245- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Adaptive optics and wavefront sensing
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Calibration and Measurement Techniques
- Molecular Spectroscopy and Structure
- Astrophysical Phenomena and Observations
- Optical Systems and Laser Technology
- Geophysics and Gravity Measurements
- Atmospheric Ozone and Climate
- Spectroscopy and Laser Applications
- Solar and Space Plasma Dynamics
- Space Exploration and Technology
- Advanced optical system design
- Astronomical and nuclear sciences
- Optical Wireless Communication Technologies
- Optical Polarization and Ellipsometry
- Galaxies: Formation, Evolution, Phenomena
- Hydrology and Sediment Transport Processes
- High-pressure geophysics and materials
- CCD and CMOS Imaging Sensors
- Particle Accelerators and Free-Electron Lasers
Université Côte d'Azur
2022-2025
Observatoire de la Côte d’Azur
2022-2025
Max Planck Institute for Astronomy
2009-2025
Université Grenoble Alpes
2015-2024
Centre National de la Recherche Scientifique
2015-2024
Institut de Planétologie et d'Astrophysique de Grenoble
2015-2024
Lagrange Laboratory
2022-2024
University of Chile
2017-2023
Institut de Biologie Valrose
2023
University of Exeter
2022
Here we show that the ~10 Myr Beta Pictoris system hosts a massive giant planet, b, located 8 to 15 AU from star. This result confirms gas planets form rapidly within disks and validates use of disk structures as fingerprints embedded planets. Among few already imaged, b is closest its parent Its short period could allow recording full orbit 17 years.
We present deep VLT/NACO infrared imaging and spectroscopic observations of the brown dwarf 2MASSWJ 1207334-393254, obtained during our on-going adaptive optics survey southern young, nearby associations. This ~25 dwarf, located ~70 pc from Earth, has been recently identified as a member TW Hydrae Association (age ~ 8 Myr). Using wavefront sensing to acquire sharp images its circumstellar environment, we discovered very faint red object at close separation ~780 mas (~55 AU). Photometry in H,...
Since the discovery of its dusty disk in 1984, Beta Pictoris has become prototype young early-type planetary systems, and there are now various indications that a massive Jovian planet is orbiting star at ~ 10 AU. However, no planets have been detected around this so far. Our goal was to investigate close environment Pic, searching for companion(s). Deep adaptive-optics L'-band images Pic were recorded using NaCo instrument Very Large Telescope. A faint point-like signal projected distance 8...
The study of dynamical processes in protoplanetary disks is essential to understand planet formation. In this context, transition are prime targets because they at an advanced stage disk clearing and may harbor direct signatures evolution. paper, we aim derive new constraints on the structure MWC 758, detect non-axisymmetric features their origin. We obtained infrared polarized intensity observations 758 with SPHERE/VLT 1.04 microns resolve scattered light a smaller inner working angle...
Young circumstellar disks are of prime interest to understand the physical and chemical conditions under which planet formation takes place. Only very few detections candidates within these exist, most them currently suspected be disk features. In this context, transition around young star PDS 70 is particular interest, due its large gap identified in previous observations, indicative ongoing formation. We aim search for presence planets structures disk-planet interactions other evolutionary...
Observations of circumstellar environments to look for the direct signal exoplanets and scattered light from disks has significant instrumental implications. In past 15 years, major developments in adaptive optics, coronagraphy, optical manufacturing, wavefront sensing data processing, together with a consistent global system analysis have enabled new generation high-contrast imagers spectrographs on large ground-based telescopes much better performance. One most productive is...
The SHINE program is a large high-contrast near-infrared survey of 600 young, nearby stars. It aimed at searching for and characterizing new planetary systems using VLT/SPHERE's unprecedented high-angular resolution imaging capabilities. also intends placing statistical constraints on the occurrence orbital properties giant planet population orbits as function stellar host mass age to test formation theories. We use IRDIS dual-band imager IFS integral field spectrograph SPHERE acquire...
Aims: We aim to characterize the orbital and atmospheric properties of PDS 70 b, which was first identified on May 2015 in course SHINE survey with SPHERE, extreme adaptive-optics instrument at VLT. Methods: obtained new deep SPHERE/IRDIS imaging SPHERE/IFS spectroscopic observations b. The astrometric baseline now covers 6 years allows us perform an analysis. For time, we present spectrophotometry young planet almost entire near-infrared range (0.96 3.8 micrometer). use different models...
We present the first near-IR scattered light detection of transitional disk associated with Herbig Ae star MWC 758 using data obtained as part Strategic Exploration Exoplanets and Disks Subaru, 1.1 micron HST/NICMOS data. While sub-millimeter studies suggested there is a dust-depleted cavity r=0.35, we find close 0.1 (20-28 AU) from star, no visible at H, K', or Ks. two small-scaled spiral structures which asymmetrically shadow outer disk. model one spirals density wave theory, derive aspect...
Context. One of the long-term goals exoplanet science is atmospheric characterization dozens small exoplanets in order to understand their diversity and search for habitable worlds potential biosignatures. Achieving this goal requires a space mission sufficient scale that can spatially separate signals from host stars thus directly scrutinize atmospheres. Aims. We seek quantify detection performance space-based mid-infrared (MIR) nulling interferometer measures thermal emission exoplanets....
We present the highest fidelity spectrum to date of a planetary-mass object. VHS 1256 b is $<$20 M$_\mathrm{Jup}$ widely separated ($\sim$8\arcsec, = 150 au), young, companion that shares photometric colors and spectroscopic features with directly imaged exoplanets HR 8799 c, d, e. As an L-to-T transition object, exists along region color-magnitude diagram where substellar atmospheres from cloudy clear. observed 1256~b \textit{JWST}'s NIRSpec IFU MIRI MRS modes for coverage 1 $\mu$m 20 at...
We present JWST Early Release Science (ERS) coronagraphic observations of the super-Jupiter exoplanet, HIP 65426 b, with Near-Infrared Camera (NIRCam) from 2-5 $\mu$m, and Mid-Infrared Instrument (MIRI) 11-16 $\mu$m. At a separation $\sim$0.82" (86$^{+116}_{-31}$ au), b is clearly detected in all seven our observational filters, representing first images an exoplanet to be obtained by JWST, ever direct detection beyond 5 These demonstrate that exceeding its nominal predicted performance up...
We report new VLT/NACO imaging observations of the young, nearby brown dwarf 2MASSW J1207334-393254 and its suggested planetary mass companion (2M1207 b). Three epochs measurements obtained over nearly one year show that candidate shares same proper motion and, with a high confidence level, is not stationary background object. This result confirms status 2M1207 b as (5 times Jupiter) first image in different system than our own. discovery offers perspectives for understanding chemical...
We report deep imaging observations of the young, nearby star AB Pic, a member large Tucana-Horologium as sociation. have detected faint, red source 5.5" South with JHK colors compatible that young substellar L dwarf. Follow-up at two additional epochs confirm, confidence level 4.7sigma, faint object is companion to Pic rather than it being stationary background object. A low resolution K-band spectrum indicates an early-L spectral type for companion. Finally, evolutionary model predictions...
<i>Context. <i/>High contrast and high angular resolution imaging is the optimal search technique for substellar companions to nearby stars at physical separations larger than typically 10 AU. Two distinct populations of companions, brown dwarfs planets, can be probed characterized. As a result, fossile traces processes formation evolution revealed by orbital properties, both individual systems as an ensemble.<i>Aims. <i/>Since November 2002, we have conducted large, deep imaging, survey...
With the uniquely high contrast within 01 (Δmag(L') = 5–6.5 mag) available using Sparse Aperture Masking with NACO at Very Large Telescope, we detected asymmetry in flux from Herbig Fe star HD 142527 a barycenter emission situated projected separation of 88 ± 5 mas (12.8 1.5 AU 145 pc) and ratios H, K, L' 0.016 0.007, 0.012 0.008, 0.0086 0.0011, respectively (3σ errors), relative to primary disk. After extensive closure-phase modeling, interpret this detection as close-in, low-mass stellar...
Direct imaging of circumstellar disks requires high-contrast and high-resolution techniques. The angular differential (ADI) technique is one them, initially developed for point-like sources but now increasingly applied to extended objects. This new field application raises many questions because the disk images reduced with ADI depend strongly on amplitude rotation data reduction strategy. Both them directly affect observable properties. Our aim characterize applicability biases some...
Direct imaging has just started the inventory of population gas giant planets on wide-orbits around young stars in solar neighborhood. Following this approach, we carried out a deep survey near-infrared using VLT/NaCo to search for substellar companions. We report here discovery L' (3.8 microns) images probable companion orbiting at 56 AU (10-17 Myr), dusty, and early-type (A8) star HD 95086. This is based observations with more than year-time-lapse. Our first epoch clearly revealed source...
In June 2010, we confirmed the existence of a giant planet in disk young star Beta Pictoris, located between 8 AU and 15 from star. This offers rare opportunity to monitor large fraction orbit using imaging technique over reasonably short timescale. Using NAOS-CONICA adaptive-optics instrument (NACO) at Very Large Telescope (VLT), obtained repeated follow-up images Bpic system Ks L' filters four new epochs 2010 2011. Complementing these data with previous measurements, conduct homogeneous...
The planetary system discovered around the young A-type HR8799 provides a unique laboratory to: a) test planet formation theories, b) probe diversity of architectures at these separations, and c) perform comparative (exo)planetology. We present exploit new near-infrared images integral-field spectra four gas giants surrounding obtained with SPHERE, finder instrument Very Large Telescope, during commissioning science verification phase (July-December 2014). With data, we contribute to...
A gas giant planet has previously been directly seen orbiting at 8-10 AU within the debris disk of ~12 Myr old star {\beta} Pictoris. The Pictoris system offers rare opportunity to study physical and atmospheric properties an exoplanet placed on a wide orbit establish its formation scenario. We obtained J (1.265 {\mu}m), H (1.66 M' (4.78 {\mu}m) band angular differential imaging between 2011 2012. detect planetary companion in our four-epoch observations. estimate = 14.0 +- 0.3, 13.5 0.2,...
Context. T Cha is a young star surrounded by cold disk. The presence of gap within its disk, inferred from fitting to the spectral energy distribution, has suggested on-going planetary formation.