Speaker: Antonia Drescher (Max Planck Institute for extraterrestrial Physics)

Title: Infrared Interferometry of the Galactic Center Black Hole

Abstract: The Galactic Center harbors the nearest massive black hole. With a distance of only 8 kpc, it is the closest laboratory to study the astrophysical processes at work in these extreme objects, and to probe Einstein's theory of general relativity in the regime of strong gravity. Our presentation gives an overview of the GRAVITY infrared interferometry observations leading to the detection of the gravitational redshift and the Schwarzschild precession in the orbit of a star orbiting the black hole in a 16 yr orbit, and the observations of orbital motion of hot gas close to the innermost stable orbit. We present the latest observations and updates on upper limits on the deviation from general relativity and any extended mass, as well as on the flare geometry and magnetic field topology.