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 [CHM2007] LDC 148. The other galaxies in the group are NGC 834, , , , and .
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 (13 million solar masses).
Supernova One supernova has been observed in NGC 818: SN 1992az (TypeII, mag. 18) was discovered by Christian Pollas on 27 September 1992.
See also List of NGC objects (1–1000)
References
External links