Black holes represent one of General Relativity’s most exotic predictions: objects so compact that they distort the fabric of spacetime. The last century has seen exciting tests of GR and the LIGO-Virgo Observatories have now definitively discovered black holes, and yet we are only beginning to approach the event horizon. Sagittarius A* is one of the most promising supermassive black holes targeted by the VLT’s GRAVITY instrument and the Event Horizon Telescope. It also offers an exciting opportunity for coordinated, multi-wavelength campaigns, which are poised to identify the origin of observed X-ray and IR variability, connect it to horizon-scale structure in the submm, and distinguish between competing models: hot spots, inflow/outflow, reconnection regions, shocks, or even magnetosphere gaps. I will review recent highlights from observations of Sgr A* and prospects for future discovery.
Host: Fred Baganoff