Publications (38)
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,…
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…
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…
The GRAVITY Young Stellar Object survey -- IX. Spatially resolved kinematics of hot hydrogen gas in the star/disk interaction region of T Tauri stars
GRAVITY Collaboration, J. A. Wojtczak, L. Labadie +58
Aims: We aim to spatially and spectrally resolve the Br-gamma hydrogen emission line with the methods of interferometry in order to examine the kinematics of the hydrogen gas emiss…
The GRAVITY Young Stellar Object survey IV. The CO overtone emission in 51 Oph at sub-au scales
GRAVITY Collaboration, M. Koutoulaki, R. Garcia Lopez +69
51 Oph is a Herbig Ae/Be star that exhibits strong near-infrared CO ro-vibrational emission at 2.3 micron, most likely originating in the innermost regions of a circumstellar disc.…
GRAVITY chromatic imaging of Eta Car's core
GRAVITY Collaboration, J. Sanchez-Bermudez, G. Weigelt +132
Eta Car is one of the most intriguing luminous blue variables in the Galaxy. Observations and models at different wavelengths suggest a central binary with a 5.54 yr period residin…
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…
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…
Accretion-ejection morphology of the microquasar SS433 resolved at sub-au scale
GRAVITY Collaboration, P. -O. Petrucci, I. Waisberg +67
We present the first optical observation at sub-milliarcsecond (mas) scale of the microquasar SS 433 obtained with the GRAVITY instrument on the VLT interferometer. The 3.5 hour ex…
The GRAVITY Young Stellar Object survey VIII. Gas and dust faint inner rings in the hybrid disk of HD141569
GRAVITY Collaboration, V. Ganci, L. Labadie +60
The formation and evolution of planetary systems impact the primordial accretion disk. HD141569 is the only known pre-main sequence star characterized by a hybrid disk. Observation…
Sub-milliarcsecond Optical Interferometry of the HMXB BP Cru with VLTI/GRAVITY
GRAVITY Collaboration, I. Waisberg, J. Dexter +68
We observe the HMXB BP Cru using interferometry in the near-infrared K band with VLTI/GRAVITY. Continuum visibilities are at most partially resolved, consistent with the predicted…
Detection of the gravitational redshift in the orbit of the star S2 near the Galactic centre massive black hole
GRAVITY Collaboration, R. Abuter, A. Amorim +95
The highly elliptical, 16-year-period orbit of the star S2 around the massive black hole candidate Sgr A* is a sensitive probe of the gravitational field in the Galactic centre. Ne…
First Light for GRAVITY: Phase Referencing Optical Interferometry for the Very Large Telescope Interferometer
GRAVITY Collaboration, R. Abuter, M. Accardo +130
GRAVITY is a new instrument to coherently combine the light of the European Southern Observatory Very Large Telescope Interferometer to form a telescope with an equivalent 130 m di…
A measure of the size of the magnetospheric accretion region in TW Hydrae
R. Garcia Lopez, A. Natta, A. Caratti o Garatti +69
Stars form by accreting material from their surrounding disks. There is a consensus that matter flowing through the disk is channelled onto the stellar surface by the stellar magne…
Experience with wavefront sensor and deformable mirror interfaces for wide-field adaptive optics systems
A. G. Basden, D. Atkinson, N. A. Bharmal +56
Recent advances in adaptive optics (AO) have led to the implementation of wide field-of-view AO systems. A number of wide-field AO systems are also planned for the forthcoming Extr…
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…
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…
The GRAVITY Young Stellar Object survey. VII. The inner dusty disks of T Tauri stars
The GRAVITY Collaboration, K. Perraut, L. Labadie +55
These protoplanetary disks in T Tauri stars play a central role in star and planet formation. We spatially resolve at sub-au scales the innermost regions of a sample of T Tauri's d…
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…
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 GRAVITY Young Stellar Object Survey. VI. Mapping the variable inner disk of HD 163296 at sub-au scales
J. Sanchez-Bermudez, A. Caratti o Garatti, R. Garcia Lopez +53
Protoplanetary disks drive some of the formation process (e.g., accretion, gas dissipation, formation of structures, etc.) of stars and planets. Understanding such physical process…
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…
The GRAVITY young stellar object survey III. The dusty disk of RY Lup
GRAVITY Collaboration, Y. -I. Bouarour, K. Perraut +55
We use PIONIER data from the ESO archive and GRAVITY data that were obtained in June 2017 with the four 8m telescopes. We use a parametric disk model and the 3D radiative transfer…
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…
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…
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…
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…
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…
The wind and the magnetospheric accretion onto the T Tauri star S Coronae Australis at sub-au resolution
R. Garcia Lopez, K. Perraut, A. Caratti o Garatti +70
To investigate the inner regions of protoplanetary disks, we performed near-infrared interferometric observations of the classical TTauri binary system S CrA. We present the first…
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 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…
MICADO: first light imager for the E-ELT
R. Davies, J. Schubert, M. Hartl +80
MICADO will equip the E-ELT with a first light capability for diffraction limited imaging at near-infrared wavelengths. The instrument's observing modes focus on various flavours o…
The GRAVITY young stellar object survey V. The orbit of the T Tauri binary star WW Cha
GRAVITY Collaboration, F. Eupen, L. Labadie +60
The young T Tauri star WW Cha was recently proposed to be a close binary object with strong infrared and submillimeter excess associated with circum-system emission. This makes WW…
Test of Einstein equivalence principle near the Galactic center supermassive black hole
A. Amorim, M. Bauböck, J. P. Berger +49
During its orbit around the four million solar mass black hole Sagittarius A* the star S2 experiences significant changes in gravitational potential. We use this change of potentia…
The GRAVITY Young Stellar Object survey -- I. Probing the disks of Herbig Ae/Be stars in terrestrial orbits
K. Perraut, L. Labadie, B. Lazareff +69
The formation and the evolution of protoplanetary disks are important stages in the lifetime of stars. The processes of disk evolution and planet formation are intrinsically linked…