Publications (72)
Infrared Detection and Characterization of Debris Disks, Exozodiacal Dust, and Exoplanets: The FKSI Mission Concept
W. C. Danchi, R. K. Barry, B. Lopez +17
The Fourier-Kelvin Stellar Interferometer (FKSI) is a mission concept for a nulling interferometer for the near-to-mid-infrared spectral region. FKSI is conceived as a mid-sized st…
Constraining the Nature of the PDS 70 Protoplanets with VLTI/GRAVITY
J. J. Wang, A. Vigan, S. Lacour +101
We present K-band interferometric observations of the PDS 70 protoplanets along with their host star using VLTI/GRAVITY. We obtained K-band spectra and 100 as precision astrome…
Direct confirmation of the radial-velocity planet Pic c
M. Nowak, S. Lacour, A. -M. Lagrange +90
Methods used to detect giant exoplanets can be broadly divided into two categories: indirect and direct. Indirect methods are more sensitive to planets with a small orbital period,…
Stability of planets in triple star systems
F. Busetti, H. Beust, C. Harley
Context: Numerous theoretical studies of the stellar dynamics of triple systems have been carried out, but fewer purely empirical studies that have addressed planetary orbits withi…
Four-of-a-kind? Comprehensive atmospheric characterisation of the HR 8799 planets with VLTI/GRAVITY
E. Nasedkin, P. Mollière, S. Lacour +95
With four companions at separations from 16 to 71 au, HR 8799 is a unique target for direct imaging, presenting an opportunity for the comparative study of exoplanets with a shared…
Can eccentric debris disks be long-lived? A first numerical investigation and application to Reticuli
V. Faramaz, H. Beust, P. Thébault +13
Imaging of debris disks has found evidence for both eccentric and offset disks. One hypothesis is that these provide evidence for massive perturbers that sculpt the observed struct…
On the AU Mic debris disk: density profiles, grain properties and dust dynamics
J. C. Augereau, H. Beust
We present the first comprehensive analysis of the AU Mic debris disk properties since the system was discovered by Kalas et al. (2004), and we explore whether the dynamical model,…
Investigating the young Solar System analog HD95086
G. Chauvin, R. Gratton, M. Bonnefoy +57
HD95086 (A8V, 17Myr) hosts a rare planetary system for which a multi-belt debris disk and a giant planet of 4-5MJup have been directly imaged. Our study aims to characterize the ph…
Hint of curvature in the orbital motion of the exoplanet 51 Eridani b using 3 years of VLT/SPHERE monitoring
A. -L. Maire, L. Rodet, F. Cantalloube +49
Context. The 51 Eridani system harbors a complex architecture with its primary star forming a hierarchical system with the binary GJ 3305AB at a projected separation of 2000 au, a…
On the origin of the wide-orbit circumbinary giant planet HD 106906: A dynamical scenario and its impact on the disk
L. Rodet, H. Beust, M. Bonnefoy +4
A giant planet has been recently resolved at a projected distance of 730 au from the tight pair of young ( 13 Myr) intermediate-mass stars HD 106906AB in the Lower Centaurus…
High resolution imaging of young M-type stars of the solar neighborhood: Probing the existence of companions down to the mass of Jupiter
P. Delorme, A. M. Lagrange, G. Chauvin +5
Context. High contrast imaging is a powerful technique to search for gas giant planets and brown dwarfs orbiting at separation larger than several AU. Around solar-type stars, gian…
VLTI/GRAVITY Observations and Characterization of the Brown Dwarf Companion HD 72946 B
W. O. Balmer, L. Pueyo, T. Stolker +96
Tension remains between the observed and modeled properties of substellar objects, but objects in binary orbits, with known dynamical masses can provide a way forward. HD 72946 B i…
On the radial distribution of giant exoplanets at Solar System scales
A. -M. Lagrange, F. Philipot, P. Rubini +5
Context. Giant planets play a major role in multiple planetary systems. Knowing their demographics is important to test their overall impact on planetary systems formation. It is a…
The HARPS search for southern extra-solar planets XVIII. An Earth-mass planet in the GJ 581 planetary system
M. Mayor, X. Bonfils, T. Forveille +10
The GJ 581 planetary system was already known to harbour three planets, including two super-Earths planets which straddle its habitable zone. We report here the detection of an add…
Dynamics of the Beta Pictoris planetary system and its falling evaporating bodies
H. Beust, J. Milli, A. Morbidelli +5
For decades, the spectral variations of Beta Pictoris have been modelled as the result of the evaporation of exocomets close to the star, termed falling evaporating bodies (FEBs).…
Post conjunction detection of Pictoris b with VLT/SPHERE
A. -M. Lagrange, A. Boccaletti, M. Langlois +102
With an orbital distance comparable to that of Saturn in the solar system, \bpic b is the closest (semi-major axis \,9\,au) exoplanet that has been imaged to orbit a star.…
High contrast at short separation with VLTI/GRAVITY: Bringing Gaia companions to light
N. Pourré, T. O. Winterhalder, J. -B. Le Bouquin +173
Since 2019, GRAVITY has provided direct observations of giant planets and brown dwarfs at separations of down to 95 mas from the host star. Some of these observations have provided…
Extrasolar planets and brown dwarfs around A-F type stars - VII. Theta Cygni radial velocity variations: planets or stellar phenomenon?
M. Desort, A. -M. Lagrange, F. Galland +23
(abridged) In the frame of the search for extrasolar planets and brown dwarfs around early-type main-sequence stars, we present the results obtained on the early F-type star Theta…
An interferometric study of the Fomalhaut inner debris disk. III. Detailed models of the exozodiacal disk and its origin
J. Lebreton, R. van Lieshout, J. -C. Augereau +15
[Abridged] Debris disks are extrasolar analogs to the solar system planetesimal belts. The star Fomalhaut harbors a cold debris belt at 140 AU as well as evidence of a warm dust co…
Chasing extreme planetary architectures: I- HD196885Ab, a super-Jupiter dancing with two stars?
G. Chauvin, M. Videla, H. Beust +21
Planet(s) in binaries are unique architectures for testing predictions of planetary formation and evolution theories in very hostile environments. We used the IRDIS dual-band image…
Two cold belts in the debris disk around the G-type star NZ Lup
A. Boccaletti, P. Thébault, N. Pawellek +36
Planetary systems hold the imprint of the formation and of the evolution of planets especially at young ages, and in particular at the stage when the gas has dissipated leaving mos…
The LAOG-Planet Imaging Surveys
G. Chauvin, A. -M. Lagrange, D. Mouillet +18
With the development of high contrast imaging techniques and infrared detectors, vast efforts have been devoted during the past decade to detect and characterize lighter, cooler an…
VLT/SPHERE astrometric confirmation and orbital analysis of the brown dwarf companion HR 2562 B
A. -L. Maire, L. Rodet, C. Lazzoni +46
Context. A low-mass brown dwarf has been recently imaged around HR 2562 (HD 50571), a star hosting a debris disk resolved in the far infrared. Interestingly, the companion location…
A new perspective on the irregular satellites of Saturn - I Dynamical and collisional history
D. Turrini, F. Marzari, H. Beust
The dynamical features of the irregular satellites of the giant planets argue against an in-situ formation and are strongly suggestive of a capture origin. Since the last detailed…
Dynamics of the TWA 7 planetary system and possibility of an additional planet
A. Lacquement, H. Beust, G. Duchêne +1
The debris disk surrounding the young star TWA 7 exhibits morphological features that tightly constrain its planetary architecture. JWST/MIRI observations have recently revealed a…
Evidence for a sub-jovian planet in the young TWA7 disk
A. -M. Lagrange, C. Wilkinson, M. Mâlin +26
Planets are thought to form from dust and gas in protoplanetary disks, and debris disks are the remnants of planet formation. Aged a few Myr up to a few Gyr, debris disks have lost…
New constrains on Gliese 86 B
A. -M. Lagrange, H. Beust, S. Udry +2
We present the results of multi epochs imaging observations of the companion to the planetary host Gliese 86. Associated to radial velocity measurements, this study aimed at charac…
Physical and orbital properties of Beta Pictoris b
M. Bonnefoy, G. -D. Marleau, R. Galicher +13
The intermediate-mass star Beta Pictoris is known to be surrounded by a structured edge-on debris disk within which a gas giant planet was discovered orbiting at 8-10 AU. The physi…
The JADE code: Coupling secular exoplanetary dynamics and photo-evaporation
M. Attia, V. Bourrier, P. Eggenberger +3
Close-in planets evolve under extreme conditions, raising questions about their origins and current nature. Two predominant mechanisms are orbital migration, which brings them clos…
ODEA: Orbital Dynamics in a complex Evolving Architecture -- Application to the planetary system HD 106906
L. Rodet, H. Beust, M. Bonnefoy +3
Mixed-variable symplectic integrators are widely used in orbital dynamics. However, they have been developed for Solar system-type architectures, and can not handle evolving hierar…
Cold and eccentric: a high-spectral resolution view of 51 Eri b with VLT/HiRISE
A. Denis, A. Vigan, G. Chauvin +35
Discovered almost 10 years ago, the giant planet 51 Eridani b is one of the least separated (0.2 arcsec) and faintest (J = 19.74 mag) directly imaged exoplanets known to date. Its…
Extrasolar planets and brown dwarfs around A-F type stars V. A planetary system found with HARPS around the F6IV-V star HD 60532
M. Desort, A. -M. Lagrange, F. Galland +4
Aims: In the frame of the search for extrasolar planets and brown dwarfs around early-type stars, we present the results obtained for the F-type main-sequence star HD 60532 (F6V) w…
A catalogue of dual-field interferometric binary calibrators
M. Nowak, S. Lacour, R. Abuter +97
Dual-field interferometric observations with VLTI/GRAVITY sometimes require the use of a "binary calibrator", a binary star whose individual components remain unresolved by the int…
Constrains on planets around beta Pic with Harps radial velocity data
A. -M. Lagrange, K. De Bondt, N. Meunier +3
Context. The β Pictoris system with its debris disk and a massive giant planet orbiting at \simeq 9 AU represents an ideal laboratory to study giant planet formation and evolution…
Planetary systems in close binary stars: the case of HD196885
G. Chauvin, H. Beust, A. -M. Lagrange +1
Planets can form and survive in close binaries, although dynamical interactions with the secondary component can actually significantly impact the giant planet formation and evolut…
Exomoon search with VLTI/GRAVITY around the substellar companion HD 206893 B
Q. Kral, J. Wang, J. Kammerer +130
Direct astrometric detection of exomoons remains unexplored. This study presents the first application of high-precision astrometry to search for exomoons around substellar compani…
The JADE code. II. Modeling the coupled orbital and atmospheric evolution of GJ 436 b to constrain its migration and companion
M. Attia, V. Bourrier, E. Bolmont +5
The observed architecture and modeled evolution of close-in exoplanets provide crucial insights into their formation pathways and survival mechanisms. To investigate these fundamen…
Direct imaging discovery of a young giant planet orbiting on Solar System scales
T. Stolker, M. Samland, L. B. F. M. Waters +102
HD 135344 AB is a young visual binary system that is best known for the protoplanetary disk around the secondary star. The circumstellar environment of the A0-type primary star, on…
The mass of Beta Pictoris c from Beta Pictoris b orbital motion
S. Lacour, J. J. Wang, L. Rodet +96
We aim to demonstrate that the presence and mass of an exoplanet can now be effectively derived from the astrometry of another exoplanet. We combined previous astrometry of Pi…
First Detection of Hydrogen in the β Pictoris Gas Disk
P. A. Wilson, A. Lecavelier des Etangs, A. Vidal-Madjar +6
The young and nearby star β Pictoris (β Pic) is surrounded by a debris disk composed of dust and gas known to host a myriad evaporating exocomets, planetesimals and at least one…
K-Stacker, an algorithm to hack the orbital parameters of planets hidden in high-contrast imaging. First applications to VLT SPHERE multi-epoch observations
H. Le Coroller, M. Nowak, P. Delorme +40
Recent high-contrast imaging surveys, looking for planets in young, nearby systems showed evidence of a small number of giant planets at relatively large separation beyond typicall…
Belt(s) of debris resolved around the Sco-Cen star HIP 67497
M. Bonnefoy, J. Milli, F. Ménard +15
In 2015, we initiated a survey of Scorpius-Centaurus A-F stars that are predicted to host warm-inner and cold-outer belts of debris similar to the case of the system HR~8799. The s…
First VLTI/GRAVITY Observations of HIP 65426 b: Evidence for a Low or Moderate Orbital Eccentricity
S. Blunt, W. O. Balmer, J. J. Wang +95
Giant exoplanets have been directly imaged over orders of magnitude of orbital separations, prompting theoretical and observational investigations of their formation pathways. In t…
Dust populations from 30 to 1000 au in the debris disk of HD 120326
C. Desgrange, J. Milli, G. Chauvin +15
Context. To date, more than a hundred debris disks have been spatially resolved. Among them, the young system HD 120326 stands out, displaying different disk substructures on both…
Dynamics of the Beta Pictoris planetary system and possibility of an additional planet
A. Lacquement, H. Beust, V. Faramaz-Gorka +1
The Pictoris system is characterized by a dusty debris disk, in addition to the presence of two already known planets. This makes it a particularly interesting case for studyi…
Constraints on the Orbit of the Young Substellar Companion GQ Lup B from High-Resolution Spectroscopy and VLTI/GRAVITY Astrometry
Vidya Venkatesan, S. Blunt, J. J. Wang +99
Understanding the orbits of giant planets is critical for testing planet formation models, particularly at wide separations greater than 10 au where traditional core accretion beco…
In-depth direct imaging and spectroscopic characterization of the young Solar System analog HD 95086
C. Desgrange, G. Chauvin, V. Christiaens +48
Context. HD 95086 is a young nearby Solar System analog hosting a giant exoplanet orbiting at 57 au from the star between an inner and outer debris belt. The existence of additiona…
Combining Gaia and GRAVITY: Characterising five new Directly Detected Substellar Companions
T. O. Winterhalder, S. Lacour, A. Mérand +96
Precise mass constraints are vital for the characterisation of brown dwarfs and exoplanets. Here we present how the combination of data obtained by Gaia and GRAVITY can help enlarg…
Orbit and atmosphere of HIP 99770 b through the eyes of VLTI/GRAVITY
T. O. Winterhalder, J. Kammerer, S. Lacour +92
Context: Inferring the likely formation channel of giant exoplanets and brown dwarf companions from orbital and atmospheric observables remains a formidable challenge. Further and…
The near-infrared spectral energy distribution of β Pictoris b
M. Bonnefoy, A. Boccaletti, A. -M. Lagrange +9
A gas giant planet has previously been directly seen orbiting at 8-10 AU within the debris disk of the ~12 Myr old star β Pictoris. The β Pictoris system offers the rare opportun…
A narrow, edge-on disk resolved around HD 106906 with SPHERE
A. -M. Lagrange, M. Langlois, R. Gratton +39
HD~106906AB is so far the only young binary system around which a planet has been imaged and a debris disk evidenced thanks to a strong IR excess. As such, it represents a unique o…
First direct detection of an exoplanet by optical interferometry; Astrometry and K-band spectroscopy of HR8799 e
S. Lacour, M. Nowak, J. Wang +85
To date, infrared interferometry at best achieved contrast ratios of a few times on bright targets. GRAVITY, with its dual-field mode, is now capable of high contrast obs…
Orbital characterization of the βPictoris b giant planet
G. Chauvin, A. -M. Lagrange, H. Beust +8
In June 2010, we confirmed the existence of a giant planet in the disk of the young star Beta Pictoris, located between 8 AU and 15 AU from the star. This young planet offers the r…
The young, tight and low mass binary TWA22AB: a new calibrator for evolutionary models ? Orbit, spectral types and temperatures determination
M. Bonnefoy, G. Chauvin, C. Dumas +7
Tight binaries discovered in young, nearby associations, with known distances, are ideal targets to provide dynamical mass measurements to test the physics of evolutionary models a…
Accurate stellar masses in the multiple system T Tau
G. Duchene, H. Beust, F. Adjali +2
The goal of this study is to obtain accurate estimates for the individual masses of the components of the tight binary system T Tau S in order to settle the ongoing debate on the n…
GG Tau: the fifth element
E. Di Folco, A. Dutrey, J. -B. Le Bouquin +9
We aim at unveiling the observational imprint of physical mechanisms that govern planetary formation in young, multiple systems. In particular, we investigate the impact of tidal t…
The GJ 504 system revisited. Combining interferometric, radial velocity, and high contrast imaging data
M. Bonnefoy, K. Perraut, A. -M. Lagrange +79
The G-type star GJ504A is known to host a 3 to 35 MJup companion whose temperature, mass, and projected separation all contribute to make it a test case for the planet formation th…
VLT/SPHERE survey for exoplanets around young, early-type stars including systems with multi-belt architectures
M. Lombart, G. Chauvin, P. Rojo +21
Dusty debris disks around pre- and main-sequence stars are potential signposts for the existence of planetesimals and exoplanets. Giant planet formation is therefore expected to pl…
Searching for substellar companion candidates with Gaia. III. Search for companions to members of young associations
A. -M. Lagrange, F. Kiefer, P. Rubini +13
Absolute astrometry with Gaia is expected to detect and characterize the orbits of thousands of exoplanets in the coming years. A tool, GaiaPMEX, was recently developed to characte…
Dynamical masses of M-dwarf binaries in young moving groups: I - The case of TWA 22 and GJ 2060
L. Rodet, M. Bonnefoy, S. Durkan +48
Evolutionary models are widely used to infer the mass of stars, brown dwarfs, and giant planets. Their predictions are thought to be less reliable at young ages ( 200 Myr) and i…
Direct discovery of the inner exoplanet in the HD206893 system. Evidence for deuterium burning in a planetary-mass companion
S. Hinkley, S. Lacour, G. -D. Marleau +110
Long term precise radial velocity (RV) monitoring of the nearby star HD206893, as well as anomalies in the system proper motion, have suggested the presence of an additional, inner…
Possible spectral lines from the gaseous Beta Pictoris disk
A. Lecavelier des Etangs, L. M. Hobbs, A. Vidal-Madjar +6
We present the results of exploratory HST observations to detect the emission lines of ions in the Beta Pic disk with the spectrograph slit placed off the star. Possible emission l…
The ExoGRAVITY survey: A K-band spectral library of giant exoplanet and brown dwarf companions
J. Kammerer, T. O. Winterhalder, S. Lacour +106
Direct observations of exoplanet and brown dwarf companions with near-infrared interferometry, first enabled by the dual-field mode of VLTI/GRAVITY, provide unique measurements of…
VLT/NACO adaptive optics imaging of the TY CrA system - A fourth stellar component candidate detected
G. Chauvin, A-M. Lagrange, H. Beust +11
We report the detection of a possible subsolar mass companion to the triple young system TY CrA using the NACO instrument at the VLT UT4 during its commissioning. Assuming for TY C…
Peering into the formation history of beta Pictoris b with VLTI/GRAVITY long baseline interferometry
GRAVITY Collaboration, M. Nowak, S. Lacour +65
Our objective is to estimate the C/O ratio in the atmosphere of beta Pictoris b and obtain an estimate of the dynamical mass of the planet, as well as to refine its orbital paramet…
Constraining the properties of HD 206893 B. A combination of radial velocity, direct imaging, and astrometry data
A. Grandjean, A. -M. Lagrange, H. Beust +25
High contrast imaging enables the determination of orbital parameters for substellar companions (planets, brown dwarfs) from the observed relative astrometry and the estimation of…
VLTI/GRAVITY Provides Evidence the Young, Substellar Companion HD 136164 Ab formed like a "Failed Star"
William O. Balmer, L. Pueyo, S. Lacour +93
Young, low-mass Brown Dwarfs orbiting early-type stars, with low mass ratios (), appear intrinsically rare and present a formation dilemma: could a handful of these…
Orbital and atmospheric characterization of the planet within the gap of the PDS 70 transition disk
A. Müller, M. Keppler, Th. Henning +43
Aims: We aim to characterize the orbital and atmospheric properties of PDS 70 b, which was first identified on May 2015 in the course of the SHINE survey with SPHERE, the extreme a…
GRAVITY K-band spectroscopy of HD 206893 B: brown dwarf or exoplanet
J. Kammerer, S. Lacour, T. Stolker +94
We aim to reveal the nature of the reddest known substellar companion HD 206893 B by studying its near-infrared colors and spectral morphology and by investigating its orbital moti…
First light of the VLT planet finder SPHERE. I. Detection and characterization of the sub-stellar companion GJ 758 B
A. Vigan, M. Bonnefoy, C. Ginski +72
GJ758 B is a brown dwarf companion to a 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 prev…
Is there really a debris disc around ?
V. Faramaz, G. Bryden, K. R. Stapelfeldt +10
The presence of a debris disc around the Gyr-old solar-type star was suggested by the infrared excess detection. Follow-up observations…
The ExoGRAVITY project: using single mode interferometry to characterize exoplanets
S. Lacour, J. J. Wang, M. Nowak +89
Combining adaptive optics and interferometric observations results in a considerable contrast gain compared to single-telescope, extreme AO systems. Taking advantage of this, the E…