Last updated on 12 July 2017
NGC 6251 is an active supergiant elliptical radio galaxy in the constellation Ursa Minor, and is more than 340 million light-years away from Earth. The galaxy has a Seyfert 2 active galactic nucleus, and is one of the most extreme examples of a Seyfert galaxy. This galaxy may be associated with gamma-ray source 3EG J1621+8203, which has high-energy gamma-ray emission. It is also noted for its one-sided radio jet—one of the brightest known—discovered in 1977. The supermassive black hole at the core has a mass of ±2.0)×108 M☉. (5.9
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- ^ "Distance and Length". Online-Unit-Converter.com. Retrieved 2010-03-29.
- ^ a b c SIMBAD
- ^ Perley, R. A.; Bridle, A. H.; Willis, A. G. (1984). "High-resolution VLA Observations of the Radio Jet in NGC 6251". Astrophysical Journal Supplement Series. 54: 291–334. Bibcode:1984ApJS...54..291P. doi:10.1086/190931.
- ^ Graham, Alister W. (November 2008), "Populating the Galaxy Velocity Dispersion - Supermassive Black Hole Mass Diagram: A Catalogue of (Mbh, σ) Values", Publications of the Astronomical Society of Australia, 25 (4): 167–175, Bibcode:2008PASA...25..167G, doi:10.1071/AS08013.
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