| Markarian 421 | |
|---|---|
| Sloan Digital Sky Survey image of Mrk 421 | |
| Observation data (Epoch J2000) | |
| Constellation | Ursa Major |
| Right ascension | 11h 04m 27.314s [1] |
| Declination | +38° 12′ 31.80″ [1] |
| Redshift | 0.030021 [1] [2] |
| Distance | 397-434 million light-years (122 [2] -133 [3] Mpc) |
| Type | BL LAC [1] [2] |
| Apparent magnitude (V) | 12.9 (SIMBAD) [1] 13.3 (NED) [2] 11.6-16 (B Band) [4] |
| Other designations | |
| B2 1101+38, UGC 6132, PGC 33452, 2E 2393, QSO B1101+384, Mark 421 [1] | |
| See also: Quasar, List of quasars | |
Markarian 421 (Mrk 421, Mkn 421) is a blazar located in the constellation Ursa Major. The object is an active galaxy and a BL Lacertae object, and is a strong source of gamma rays. It is about 397 million light-years (redshift: z=0.0308 eq. 122Mpc) [2] to 434 million light-years (133Mpc) [3] from the Earth. It is one of the closest blazars to Earth, making it one of the brightest quasars in the night sky. It is suspected to have a supermassive black hole (SMBH) at its center due to its active nature. An early-type high inclination spiral galaxy (Markarian 421-5) is located 14 arc-seconds northeast of Markarian 421.
It was first determined to be a very high energy gamma ray emitter in 1992 by M. Punch at the Whipple Observatory, [5] and an extremely rapid outburst in very-high-energy gamma rays (15-minute rise-time) was measured in 1996 by J. Gaidos at Whipple Observatory. [6]
Markarian 421 also had an outburst in 2001 and is monitored by the Whole Earth Blazar Telescope project. [7]
Due to its brightness (around 13.3 magnitude, max. 11.6 mag. and min. 16 mag.) the object can also be viewed by amateurs in smaller telescopes.