Alternate Names

Sagittarius A*

Type

Supermassive

Location

In the constellation Sagittarius

Finder Chart

Distance

27,000 light-years (8 kiloparsecs)

Mass

4.1 million times the mass of the Sun

Size

Diameter roughly 15 million miles (24 million km).

Discovery Methods

• Measuring the motions of stars

1

The supermassive black hole at the center of our Milky Way galaxy lies behind dense clouds of gas and dust. The center of the galaxy is a little above the "spout" of the teapot-shaped constellation Sagittarius at the upper right of this photograph. It's about 27,000 light-years away. Recent observations show that the black hole occasionally produces flares of energy, perhaps caused by its complex magnetic field. [Akira Fujii]

This document was last modified: August 21, 2006.