NGC 818


NGC 818 is an intermediate spiral galaxy in the constellation of Andromeda. Its velocity with respect to the cosmic microwave background is, which corresponds to a Hubble distance of. Additionally, 14 non-redshift measurements give a closer mean distance of. It was discovered by German-British astronomer William Herschel on 18 October 1786.
NGC 818 has a possible active galactic nucleus, i.e. it has a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum, with characteristics indicating that this luminosity is not produced by the stars.

Galaxy group

NGC 818 is a member of a galaxy group known as LDC 148. The other galaxies in the group are NGC 834, NGC 841, NGC 845, UGC 1673, and UGC 1721.

Supermassive black hole

According to a paper based on measurements of the near-infrared K-band luminosity of the galaxy's bulge, NGC 818 has a supermassive black hole with a mass of .

Supernova

One supernova has been observed in NGC 818:SN 1992az was discovered by Christian Pollas on 27 September 1992.