NGC 4051

NGC 4051 is an intermediate spiral galaxy in the constellation of Ursa Major. It was discovered on 6 February 1788 by John Herschel.

NGC 4051 contains a supermassive black hole with a mass of 1.73 million Solar mass. This galaxy was studied by the Multicolor Active Galactic Nuclei Monitoring 2m telescope.

Three supernovae have been discovered in NGC 4051: SN 1983I (type Ic, mag. 13.5), SN 2003ie (type II, mag. 15.2), and SN 2010br (type Ib/c, mag. 17.7).

The galaxy is a Seyfert galaxy that emits bright X-rays. However, in early 1998 the X-ray emission ceased as observed by the Beppo-SAX satellite. X-ray emission had risen back to normal by August 1998.

NGC 4051 is a member of the Ursa Major Cluster. Its peculiar velocity is &minus;490 ± 34 km/s, consistent with the rest of the cluster.