Markarian 177

Markarian 177 is a blue compact^[5] dwarf galaxy located 90,000,000 ly (28 Mpc) away, at the constellation of Ursa Major, in the bowl of the Big Dipper asterism.^[2] It was discovered by the astronomer Benjamin Markarian.

Markarian 177
Observation data (J2000.0[1] epoch)
Constellation	Ursa Major[2]
Right ascension	11h 33m 23.474s[1]
Declination	+55° 04′ 20.10″[1]
Redshift	0.008088[1]
Distance	90,000,000 ly (28 Mpc)[2] h−1 0.678
Apparent magnitude (V)	15.7[1]
Notable features	SDSS J113323.97+550415.8 — Ejected supermassive black hole[3]
Other designations
Markarian 177, MKR 177, MKN 177, MRK 177, Mark 177, 2MASX J11332348+5504204,[4] SDSS J113323.47+550420.6,[1] PGC 35678,[1] LEDA 35678,[4] UGCA 239[1]

Markarian 177 is a peculiar galaxy^[5] that is receding from us at a rate of 2425 km/s. It has a visual apparent size of 0.41×0.34 arcmin.^[1]

SDSS1133

Near the galaxy, at over 2,600 ly (800 pc) from it, is a luminous X-ray source named SDSS J113323.97+550415.8 (SDSS1133), in orbit around Markarian 177. The source has been stable for some decades from the 1950s through the 2000s, and the emission region is some 40 ly (12 pc) wide. It may be an ejected supermassive black hole from a galaxy that interacted with Markarian 177.

Alternative explanations for the X-ray source include it possibly being a luminous blue variable star that has recently undergone a supernova in the early 2000s, where for the previous five decades it had been in continuous eruption.^[2][3][6]

Further reading

• Michael Koss; Laura Blecha; Richard Mushotzky; Chao Ling Hung; Sylvain Veilleux; Benny Trakhtenbrot; Kevin Schawinski; Daniel Stern; Nathan Smith; Yanxia Li; Allison Man; Alexei V. Filippenko; Jon C. Mauerhan; Kris Stanek; David Sanders (27 January 2014). "SDSS1133: An Unusually Persistent Transient in a Nearby Dwarf Galaxy". Monthly Notices of the Royal Astronomical Society. 445 (1) (published November 2014): 515–527. arXiv:1401.6798. Bibcode:2014MNRAS.445..515K. doi:10.1093/mnras/stu1673.