In the last decade we have found supermassive black holes in the centers of individual galaxies and most of the evidence comes from stars orbiting close to the dense central region.

Observations with radio telescopes and the Hubble Space Telescope have found strong evidence for a humongous black hole in the center of almost every large galaxy close enough for us to observe. These supermassive black holes have typical masses millions of times the mass of our sun. They let their presence be known by causing stars and gas close to them to orbit at incredibly fast speeds.