images

Spiral galaxy M81 in Ursa Major

by

E.Mouquet/Novapix

Reference

a-gax30-31051

Date

2007-01-16

M81 is the brightest member of the nearby galactic group called the M81 group. It is located about 12 million light years away. M81 has the distinction of being the nearest spiral galaxy to have an active galactic nucleus (AGN). AGN galaxies are luminous galaxies that demonstrate much of their luminosity as nonstellar emission arising from their nucleus. The modern interpretation for the unusual energy output is the presence of a super massive black hole which consumes infalling matter from a rotating accretion disk in the galaxy's center.