Alternate Names

NGC 3031

Type

Supermassive

Location

in the constellation Ursa Major

Finder Chart

Distance

12 million light-years (3.9 megaparsecs)

Mass

7 million times the mass of the Sun

Size

Diameter roughly 30 million miles (45 million km), about 30 times the diameter of the Sun.

Discovery Methods

• Measuring the motions of gas

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.