The material surrounding accreting supermassive black holes connects the active galactic
nucleus with its host galaxy and, besides being responsible for feeding the black hole …

Most galactic nuclei harbor a massive black hole (MBH), whose birth and evolution are
closely linked to those of its host galaxy. The unique conditions near the MBH—high velocity …

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 …

Using 25 years of data from uninterrupted monitoring of stellar orbits in the Galactic Center,
we present an update of the main results from this unique data set: a measurement of mass …

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 …

Einstein's General theory of relativity (GR) successfully describes gravity. Although GR has
been accurately tested in weak gravitational fields, it remains largely untested in the general …

Very long baseline interferometric observations have resolved structure on scales of only a
few Schwarzschild radii around the supermassive black holes at the centers of our Galaxy …

We present the results of an extensive high-resolution imaging survey of M-dwarf multiplicity
using the Lucky Imaging technique. The survey made use of the AstraLux Norte camera at …

Context. This is the second of three papers that search for the predicted stellar cusp around
the Milky Way's central black hole, Sagittarius A*, with new data and methods. Aims. We aim …

The black hole in the center of the Milky Way, Sgr A*, has the largest mass-to-distance ratio
among all known black holes in the universe. This property makes Sgr A* the optimal target …