NGC 3891 is a large spiral galaxy in the constellation of Ursa Major. Its velocity with respect to the cosmic microwave background is 6,581±20 km/s, which corresponds to a Hubble distance of 316.6 ± 22.2 Mly (97.06 ± 6.80 Mpc). However, 10 non-redshift measurements give a slightly farther mean distance of 330.46 ± 14.72 Mly (101.320 ± 4.514 Mpc). It was discovered by German-British astronomer William Herschel on 3 February 1788.
NGC 3891 is a LINER galaxy, i.e. a galaxy whose nucleus has an emission spectrum characterized by broad lines of weakly ionized atoms. It is also a radio galaxy, i.e. it has giant regions of radio emission extending well beyond its visible structure.
NGC 3891 is a member of the Coma cluster.
Supernovae
Two supernovae have been observed in NGC 3891:
- SN 2006or (Type Ia, mag. 16.3) was discovered by Tim Puckett and A. Kroes on 18 November 2006.
- SN 2018bdv (Type II-P, mag. 18.53) was discovered by Gaia Photometric Science Alerts on 29 April 2018.
