A5028103745- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Adaptive optics and wavefront sensing
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Calibration and Measurement Techniques
- Astrophysical Phenomena and Observations
- Molecular Spectroscopy and Structure
- Optical Polarization and Ellipsometry
- Optical Systems and Laser Technology
- Atmospheric Ozone and Climate
- Solar and Space Plasma Dynamics
- Advanced optical system design
- Spacecraft and Cryogenic Technologies
- Planetary Science and Exploration
- Geological and Geochemical Analysis
- Radio Astronomy Observations and Technology
- Bee Products Chemical Analysis
- Geophysics and Gravity Measurements
- Astrophysics and Cosmic Phenomena
- Nuclear physics research studies
- Infrared Target Detection Methodologies
- Particle physics theoretical and experimental studies
Osservatorio Astronomico di Padova
2015-2024
National Institute for Astrophysics
2011-2024
Université de Versailles Saint-Quentin-en-Yvelines
2022
Sorbonne Université
2022
Université Paris Cité
2022
Laboratoire d’études spatiales et d’instrumentation en astrophysique
2022
Observatoire de Paris
2022
Centre National de la Recherche Scientifique
2022
University of Minnesota Rochester
2020-2021
Institute for Space Astrophysics and Planetology
2016-2021
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...
Aims. Using the direct imaging technique we searched for low mass companions around star AF Lep that presents a significant proper motion anomaly (PMa) signal obtained from comparison of Hipparcos and Gaia eDR3 catalogs. Methods. We observed in two epochs with VLT/SPHERE using its subsystems IFS IRDIS near-infrared (NIR) covering wavelengths ranging Y to K spectral bands (between 0.95 2.3 {\mu}m). The data were then reduced high-contrast techniques angular differential (ADI) (SDI) be able...
We present detailed predictions of the contributions various source populations to counts at frequencies tens GHz. New evolutionary models are worked out for flat-spectrum radio quasars, BL Lac objects, and steep-spectrum sources. Source characterized by spectra peaking high frequencies, such as extreme GPS sources, ADAF/ADIOS sources early phases γ-ray burst afterglows also dealt with. The different star-forming galaxies (normal spirals, starbursts, high-z detected SCUBA MAMBO surveys,...
As the only directly imaged multiple planet system, HR 8799 provides a unique opportunity to study physical properties of several planets in parallel. In this paper, we image all four at H-band and 3.3 microns with new LBT adaptive optics PISCES, LBTI/LMIRCam. Our images offer an unprecedented view allowing us obtain H 3.3$ micron photometry innermost (for first time) put strong upper-limits on presence hypothetical fifth companion. We find that are unexpectedly bright compared equilibrium...
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...
51 Eridani b is an exoplanet around a young (20 Myr) nearby (29.4 pc) F0-type star, recently discovered by direct imaging. Being only 0.5" away from its host star it well suited for spectroscopic analysis using integral field spectrographs. We aim to refine the atmospheric properties of this and further constrain architecture system searching additional companions. Using SPHERE instrument at VLT we extend spectral coverage planet complete Y- H-band range provide photometry in K12-bands...
Understanding the diversity of planets requires to study morphology and physical conditions in protoplanetary disks which they form. We observed spatially resolved disk around ~10 Myr old HD 100453 polarized scattered light with SPHERE/VLT at optical near-infrared wavelengths, reaching an angular resolution ~0.02", inner working angle ~0.09". detect up ~0.42" (~48 au) a cavity, rim azimuthal brightness variations inclination 38 degrees, two shadows symmetric spiral arms. The arms originate...
We present the performance of Integral Field Spectrograph (IFS) SPHERE, high-contrast imager for ESO VLT telescope designed to perform imaging and spectroscopy extrasolar planets, obtained from tests performed at Institute de Plan\'etologie et d'Astrophysique Grenoble facility during integration phase instrument.} {The were using instrument software purposely prepared SPHERE. The output data reduced applying SPHERE reduction handling software, adding an improved spectral deconvolution...
The system of four planets around HR8799 offers a unique opportunity to probe the physics and chemistry at play in atmospheres self-luminous young (~30 Myr) planets. We recently obtained new photometry low-resolution (R~30) spectra d e with SPHERE instrument (paper III). In this paper IV), we compare available known objects atmospheric models (BT-SETTL14, Cloud-AE60, Exo-REM) characterize properties find that HR8799d are well reproduced by those L6-L8 dusty dwarfs discovered field, among...
[Abridged] Context. The young systems PZ Tel and HD 1160, hosting known low-mass companions, were observed during the commissioning of new planet finder SPHERE with several imaging spectroscopic modes. Aims. We aim to refine physical properties architecture both systems. Methods. use data REM observations, as well literature unpublished from VLT/SINFONI, VLT/NaCo, Gemini/NICI, Keck/NIRC2. Results. derive photometry confirm nearly daily photometric variability A. Using spanning 38 yr, we show...
In anticipation of the VLT/SPHERE planet imager guaranteed time programs, we have conducted a preparatory survey 86 stars between 2009 and 2013 in order to identify new faint comoving companions ultimately carry out comprehensive analysis occurence giant planets brown dwarf at wide (10-2000 AU) orbits around young, solar-type stars. We used NaCo VLT explore occurrence rate dwarfs typically 0.1 8''. Diffraction-limited observations H-band combined with angular differential imaging enabled us...
Understanding the formation and evolution of giant planets ($\ge$1 $M_{Jup}$) at wide orbital separation ($\ge$5 AU) is one goals direct imaging. Over past 15 years, many surveys have placed strong constraints on occurrence rate wide-orbit giants, mostly based non-detections, but very few tried to make a link with planet theories. In present work, we combine results our previously published VLT/NaCo large program 12 imaging constitute statistical sample 199 FGK stars within 100 pc, including...
HR4796A is surrounded by a debris disc, observed in scattered light as an inclined ring. Past observations raised several questions. First, strong brightness asymmetry detected polarized reflected recently challenged our understanding of scattering the dust particles this system. Secondly, morphology ring strongly suggests presence planets, although no planets have been to date. We obtained high-angular resolution coronagraphic images circumstellar environment around with VLT/SPHERE during...
GJ758 B is a brown dwarf companion to nearby (15.76 pc) solar-type, metal-rich (M/H = +0.2 dex) main-sequence star (G9V) that was discovered with Subaru/HiCIAO in 2009. From previous studies, it has drawn attention as being the coldest (~600K) ever directly imaged around neighboring star. We present new high-contrast data obtained during commissioning of SPHERE instrument at VLT. The Y-, J-, H-, and Ks-bands dual-band imaging (DBI) mode IRDIS, providing broad coverage full near-infrared...
Sirius has always attracted a lot of scientific interest, especially after the discovery companion white dwarf at end 19th century. Very early on, existence potential third body was put forward to explain some observed properties system. We present new coronagraphic observations obtained with VLT/SPHERE that explore, for very first time, innermost regions system down 0.2" (0.5 AU) from A. Our cover near-infrared 0.95 2.3 $\mu$m and they offer best on-sky contrast ever reached these angular...
We image with unprecedented spatial resolution and sensitivity disk features that could be potential signs of planet-disk interaction. Two companion candidates have been claimed in the around young Herbig Ae/Be star HD100546. Thus, this object serves as an excellent target for our investigation natal environment giant planets. exploit power extreme adaptive optics operating conjunction new high-contrast imager SPHERE to HD100546 scattered light. obtain first polarized light observations...
Context. In recent decades, direct imaging has confirmed the existence of substellar companions (exoplanets or brown dwarfs) on wide orbits (>10 au) around their host stars. striving to understand formation and evolution mechanisms, in 2015 we initiated SPHERE infrared survey for exoplanets (SHINE), a systematic young, nearby stars that is targeted at exploring demographics. Aims. We aim detect characterize population giant planets dwarfs beyond snow line Combined with completeness, our...
Context. Large surveys with new-generation high-contrast imaging instruments are needed to derive the frequency and properties of exoplanet populations separations from ~5 300 au. A careful assessment stellar is crucial for a proper understanding when, where, how frequently planets form, they evolve. The sensitivity detection limits age makes this key parameter direct surveys. Aims. We describe SpHere INfrared survey Exoplanets (SHINE), largest planet-search campaign initiated at VLT in 2015...