NGC 6331
Galaxy in the constellation Ursa Minor
From Wikipedia, the free encyclopedia
NGC 6331 is a type E[1] elliptical galaxy located in the Ursa Minor constellation.[2][1] It is located 737 million light-years from the Solar System[3] and was discovered by German-British astronomer William Herschel on December 20, 1797, utilizing an 18.7-inch f/13 spectrum telescope[4] but also observed by Guillaume Bigourdan.[5]
| NGC 6331 | |
|---|---|
SDSS image of NGC 6331 | |
| Observation data (J2000 epoch) | |
| Constellation | Ursa Minor |
| Right ascension | 17h 03m 35.97s |
| Declination | +78d 37m 44.40s |
| Redshift | 0.053614 0.00150 |
| Heliocentric radial velocity | 17,570 km/s |
| Distance | 737 Mly (226 Mpc) |
| Group or cluster | Abell 2256 |
| Apparent magnitude (V) | 14.4 |
| Characteristics | |
| Type | E |
| Size | 345,000 ly |
| Other designations | |
| PGC 84830, 2MASX J17033591+7837435, SDSS J170335.88+783744.0, NSA 167203, WBL 631-001, CGCG 355-024, MCG +013-12-015 | |
With an approximate diameter of 345,000 light-years, NGC 6331 is well considered one of the largest galaxies.[3] It is the brightest group member of Abell 2256 and first in 6' string to the east, making up of 6 galaxies.[6] NGC 6331 also makes up a part of the galactic triplet CGCG 355-024[7] which comprises two other elliptical galaxies in the cluster, CGCG 355-024 NED03 (PGC 59513)[8] and CGCG 355-024 NED01 (PGC 84827).[9]