activity
20102025
most citedDetection of the gravitational redshift in the orbit of the star S2 near the Galactic centre massive black hole

947 citations · 5.5k across the 56 of their papers we have counts for

collaborators

56 papers

astro-ph.EP2025★ 8 cited

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…

astro-ph.EP2025★ 6 cited

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…

astro-ph.EP2025

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…

astro-ph.IM2025★ 8 cited

First Light for the GRAVITY+ Adaptive Optics: Extreme Adaptive Optics for the Very Large Telescope Interferometer

GRAVITY+ Collaboration, :, F. Allouche +137

GRAVITY+ improves by orders of magnitude the sensitivity, sky-coverage and contrast of the Very Large Telescope Interferometer (VLTI). A central part of this project is the develop…

astro-ph.EP2025

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…

astro-ph.EP2025

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…

astro-ph.IM2025★ 1 cited

GRAVITY+ adaptive optics (GPAO) tests in Europe

Florentin Millour, Guillaume Bourdarot, Jean-Baptiste Le Bouquin +54

We present in this proceeding the results of the test phase of the GRAVITY+ adaptive optics. This extreme AO will enable both high-dynamic range observations of faint companions (i…

astro-ph.IM2024★ 1 cited

GRAVITY+ Wavefront Sensors: High-Contrast, Laser Guide Star, Adaptive Optics systems for the VLTI

G. Bourdarot, F. Eisenhauer, S. Yazıcı +53

We present the Wavefront Sensor units of the Gravity Plus Adaptive Optics (GPAO) system, which will equip all 8m class telescopes of the VLTI and is an instrumental part of the GRA…

astro-ph.IM2024

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…

astro-ph.EP2024

Astrometric detection of a Neptune-mass candidate planet in the nearest M-dwarf binary system GJ65 with VLTI/GRAVITY

GRAVITY Collaboration, R. Abuter, A. Amorim +65

The detection of low-mass planets orbiting the nearest stars is a central stake of exoplanetary science, as they can be directly characterized much more easily than their distant c…

astro-ph.EP2024★ 54 cited

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…

astro-ph.SR2023

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…

astro-ph.EP2023

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…

astro-ph.SR2023★ 15 cited

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…

astro-ph.IM2022

GRAVITY+ Wide: Towards hundreds of z 2 AGN

A. Drescher, M. Fabricius, T. Shimizu +34

As part of the GRAVITY project, the near-infrared beam combiner GRAVITY and the VLTI are currently undergoing a series of significant upgrades to further improve the performa…

astro-ph.IM2022

GRAVITY faint: reducing noise sources in GRAVITY with a fast metrology attenuation system

F. Widmann, S. Gillessen, T. Ott +28

With the upgrade from GRAVITY to GRAVITY the instrument will evolve into an all-sky interferometer that can observe faint targets, such as high redshift AGN. Observing the fain…

astro-ph.EP2022★ 79 cited

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…

astro-ph.IM2022★ 31 cited

First Light for GRAVITY Wide: Large Separation Fringe Tracking for the Very Large Telescope Interferometer

GRAVITY+ Collaboration, :, R. Abuter +114

GRAVITY+ is the upgrade of GRAVITY and the Very Large Telescope Interferometer (VLTI) with wide-separation fringe tracking, new adaptive optics, and laser guide stars on all four 8…

astro-ph.GA2021★ 287 cited

The mass distribution in the Galactic Centre from interferometric astrometry of multiple stellar orbits

GRAVITY Collaboration, R. Abuter, N. Aimar +62

The stars orbiting the compact radio source Sgr A* in the Galactic Centre are precision probes of the gravitational field around the closest massive black hole. In addition to adap…

astro-ph.GA2021★ 35 cited

Deep Images of the Galactic Center with GRAVITY

GRAVITY Collaboration, R. Abuter, N. Aimar +65

Stellar orbits at the Galactic Center provide a very clean probe of the gravitational potential of the supermassive black hole. They can be studied with unique precision, beyond th…

astro-ph.EP2021★ 86 cited

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 Pic…

astro-ph.HE2021★ 64 cited

Constraining particle acceleration in Sgr A* with simultaneous GRAVITY, Spitzer, NuSTAR and Chandra observations

R. Abuter, A. Amorim, M. Bauböck +81

We report the time-resolved spectral analysis of a bright near-infrared and moderate X-ray flare of Sgr A*. We obtained light curves in the -, -, and -bands in the mid- an…

astro-ph.EP2021★ 27 cited

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…

astro-ph.SR2021★ 4 cited

MOLsphere and pulsations of the Galactic Center's red supergiant GCIRS 7 from VLTI/GRAVITY

GRAVITY Collaboration, G. Rodríguez-Coira, T. Paumard +55

GCIRS 7, the brightest star in the Galactic central parsec, formed Myr ago together with dozens of massive stars in a disk orbiting the central black-hole. It has been argu…