Markarian 421

Markarian 421

Hubble Legacy Archive WFPC2 image of Mark 421 and its companion galaxy 421-5
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, and has a companion galaxy (Markarian 421-5) that is fueling the gas jets observed pointing away from the galaxy.

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. 11.6mag. and min. 16mag.) the object can also be viewed by amateurs in smaller telescopes.

References

Coordinates: 11h 04m 27s, +38° 12′ 32″


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