NGC 3998

NGC 3998 is a lenticular galaxy located approximately 45 million light-years away in the constellation Ursa Major. It is classified as a LINER galaxy, indicating that its nucleus exhibits weak emission lines of ionized atoms. This emission is thought to be powered either by a weak active galactic nucleus (AGN) or by star formation.

NGC 3998 is notable for possessing a supermassive black hole at its center, estimated to be around 55 million times the mass of the Sun. The galaxy also has a relatively bright radio emission, further suggesting the presence of an AGN, albeit a weak one.

The galaxy is relatively isolated, without any major nearby companion galaxies interacting with it. Observations have revealed the presence of a faint outer ring structure surrounding the main galactic disk, which may be the result of past minor mergers or accretion events.

NGC 3998 is a frequent target of astronomical studies due to its relatively close proximity, its LINER classification, and the presence of a supermassive black hole. Its properties provide insights into the evolution and activity of lenticular galaxies and the nature of AGNs.