Sagittarius A* (pronounced “Sagittarius A-Star”, abbreviated Sgr A*) is a bright and very compact astronomical radio source at the center of the Milky Way, near the border of the constellations Sagittarius and Scorpius. It is likely the location of a supermassive black hole, similar to those generally accepted to be at the centers of most if not all spiral and elliptical galaxies.

Observations of a number of stars orbiting around Sagittarius A*, most notably the star S2, have been used to provide evidence for the presence of, and produce data about, the Milky Way’s hypothesized central supermassive black hole, and have led some scientists to conclude that Sagittarius A* is beyond any reasonable doubt the site of that black hole. Distance 22 pc