Infrared Interferometry and the 2018 Galactic Center Peri-Center Passage of the star S2

The Center of our Galaxy is a unique laboratory for exploring the astrophysics around a massive black hole and testing General Relativity and other theoretical concepts in this extreme environment. I will discuss the results of a major campaign of observing the Galactic Center in 2017/2108 with three instruments at the European Southern Observatory's VLT, including the novel GRAVITY interferometric beam combiner of the 4 UTs. During this period the B-star S2 completed a peri-passage at ~1400 R_S, and permitted for the first time a test of the equivalence principle and the detection of the first post-Newtonian orbital elements in a classical 'clock experiment' around a massive black hole.

Speaker: Reinhard Genzel, UC Berkeley