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 …

The broadening of atomic emission lines by high-velocity motion of gas near accreting
supermassive black holes is an observational hallmark of quasars. Observations of broad …

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. Near …

This paper provides a general introduction to the problem of image reconstruction from
interferometric data. A simple model of the interferometric observables is given, and the …

Context. β Pictoris is arguably one of the most studied stellar systems outside of our own.
Some 30 yr of observations have revealed a highly-structured circumstellar disk, with rings …

We report the detection of continuous positional and polarization changes of the compact
source SgrA* in high states (“flares”) of its variable near-infrared emission with the near …

Young stars are surrounded by a circumstellar disk of gas and dust, within which planet
formation can occur. Gravitational forces in multiple star systems can disrupt the disk …

Context. Optical long-baseline interferometry is moving a crucial step forward with the
advent of general-user scientific instruments that equip large aperture and hectometric …

We measured the radii of 7 low and very low-mass stars using long baseline interferometry
with the VLTI interferometer and its VINCI and AMBER near-infrared recombiners. We use …

Context. The GRAVITY instrument was commissioned on the VLTI in 2016 and is now
available to the astronomical community. It is the first optical interferometer capable of …