Sagittarius A*, abbreviated Sgr A*, is the supermassive black hole (or z-pinch node, if you are an electric universe proponent) at the Galactic Center of the Milky Way. It is located near the border of the constellations Sagittarius and Scorpius, about 5.6° south of the ecliptic, visually close to the Butterfly Cluster and Lambda Scorpii. Wikipedia
Radius: 7.4565 million mi
Distance to Earth: 25,640 light years
Discovered: February 13, 1974
Coordinates: RA 17h 45m 40s | Dec -29° 0′ 28″
Constellation: Sagittarius
Discoverers: Reinhard Genzel, Harry Clive Minnett, Robert Brown, Bruce Balick
Mass
How much mass does sagittarius a have
From examining the Keplerian orbit of S2, they determined the mass of Sagittarius A* to be 4.1±0.6 million solar masses, confined in a volume with a radius no more than 17 light-hours (120 AU ).