The Galactic Center black hole with GRAVITY: detection of orbital motion close to the last stable orbit during a flare, and general relativistic effects in the orbit of a stars

February 14, 2019
Phillips Auditorium
MPE
Abstract: 

The Galactic Center offers the rare possibility to quantitatively test general relativity in the so-far unexplored regime close to a massive black hole. Here we present the main results from the last two years of GRAVITY observations: the detection of the gravitational redshift in the orbit of the star S2, and the detection of orbital motion close to the last stable orbit during a flare. The GRAVITY instrument, which we have developed specifically for the observations of the Galactic Center black hole and its orbiting stars, is now routinely achieving ~3 milli-arcsec imaging interferometry with a sensitivity several hundred times better than previous instruments. Its astrometric precision of few ten micro arcseconds corresponds to only few Schwarzschild radii of Galactic Center massive black hole, which opens up the possibility to test the fundamentals of gravity all the way from the underlying equivalence principles, to considerations on new physics and their characteristic scales and strengths.

Event Status: 
Active