Type

Supermassive

Location

In the constellation Sagittarius

Finder Chart

Distance

27,000 light-years (0.008 megaparsecs)

Mass

2.6 million to 4 million times the mass of the Sun

Size

Diameter roughly 10 million-15 million miles (16-24 million km).

Discovery Methods

• Measuring the motions of stars

An ultraviolet view of M81 from Europe’s orbiting XMM-Newton X-ray telescope. The bright dot in the center represents the hot accretion disk that encircles the central black hole. [Alice Breeveld, University College, London]

This document was last modified: October 24, 2005.