Sagittarius 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 best explained as a super massive black hole with a mass of 4.1 - 4.5 million times the mass of the Sun.

Radius: 13.670166 million mi

Distance to Earth: 25,640 light years

Discovered: February 13, 1974

Constellation: Sagittarius

Coordinates: RA 17h 45m 40s | Dec -29° 0′ 28″

Did you know: Astronomers have observed stars spinning around the super massive black hole in Sagittarius A*.