| NGC 2985 | |
|---|---|
 NGC 2985 byHubble Space Telescope.[1] | |
| Observation data (J2000epoch) | |
| Constellation | Ursa Major |
| Right ascension | 09h 50m 22.2s[2] |
| Declination | +72° 16′ 43″[2] |
| Redshift | 0.004410 ± 0.0000237[2] |
| Heliocentric radial velocity | 1,322 ± 7km/s[2] |
| Distance | 70.1 ± 4.1Mly (21.5 ± 1.3Mpc)[2] |
| Apparent magnitude (V) | 10.4[3] |
| Characteristics | |
| Type | (R')SA(rs)ab[2] |
| Apparent size (V) | 4.6′ × 3.6′[2] |
| Other designations | |
| UGC 5253, CGCG 332-067,MCG +12-10-006,PGC 28316[2] | |
NGC 2985 is aspiral galaxy located in the constellationUrsa Major. It is located at a distance of circa 70 millionlight years from Earth, which, given its apparent dimensions, means that NGC 2985 is about 95,000 light years across. It was discovered byWilliam Herschel on April 3, 1785.[4]
The galaxy is seen with an inclination of 37 degrees.[5] The galaxy has a bright nucleus from which emanate multiple tightly woundspiral fragments.[6] Numerous blue knots are visible at thegalactic disk. At the outer part of the galaxy lies a massive spiral arm that forms a pseudoring that encircles the galaxy. The inner part of the galaxy, where activestar formation has been observed, has been found to be unstable, contrary to the outer stable one. It has been suggested that the presence ofmolecular clouds accounts for the instability of the region.[5]
The nucleus of NGC 2985 isactive, and based on its spectrum has been categorised as aLINER. The most accepted theory for the activity source is the presence of anaccretion disk around a supermassive black hole. The mass of the supermassive black hole at the centre of NGC 2985 is estimated to be 160 million (108.2)M☉, based on stellarvelocity dispersion.[7] The velocity dispersion isanisotropic, and changes with theazimuth. The rotational speed of the galaxy at itseffective radius is 222.9 ± 31.2 km/s.[8]
NGC 2985 is the brightest member of agalaxy group known as the NGC 2985 group. Other members of the group includeNGC 3027, 25 arcminutes away. Other nearby galaxies includeNGC 3252, andNGC 3403.[9]
