| NGC 4556 | |
|---|---|
 SDSS image of NGC 4556. | |
| Observation data (J2000epoch) | |
| Constellation | Coma Berenices |
| Right ascension | 12h 35m 45.8s[1] |
| Declination | 26° 54′ 32″[1] |
| Redshift | 0.024764[1] |
| Heliocentric radial velocity | 7424 km/s[1] |
| Distance | 340 Mly (105 Mpc) |
| Apparent magnitude (V) | 13.8[1] |
| Absolute magnitude (B) | -22.89[1] |
| Characteristics | |
| Type | cD, E+[1] |
| Size | ~167,500 ly (51.36 kpc) (estimated)[1] |
| Apparent size (V) | 1.35′ × 0.93′[1] |
| Other designations | |
| UGC 07765, CGCG 159-022, MCG +05-30-027, PGC 041980[1] | |
NGC 4556 is anelliptical galaxy and acD galaxy located 340 millionlight-years away[2] in theconstellationComa Berenices. It was discovered on April 11, 1785, by astronomerWilliam Herschel.[3] NGC 4556 is a member of a group of 12 galaxies known as [T2015] nest 100082, or theNGC 4555 Group,[4] and is part of theComa Supercluster.[5][6]
NGC 4556 is host to asupermassive black hole with an estimated mass of 1.1 × 109M☉.[7]