NGC 6251 explained

NGC 6251
Ra:	^[1]
Z:	0.02471
Type:	E
Dist Ly:	340 million light-years^[2]
Appmag V:	14.3
Size V:	1.82´X1.55´
Names:	NGC 6251, UGC 10501, LEDA 58472, 6C 1636+8239, QSO B1637+826

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,^[3] 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.^[3] It is also noted for its one-sided radio jet—one of the brightest known—discovered in 1977.^[4] The supermassive black hole at the core has a mass of .

External links

• • www.jb.man.ac.uk/atlas/
• Wikisky image of NGC 6251
• Hubble Finds a Bare Black Hole Pouring Out Light (Probing the heart of the active galaxy NGC 6251—September 10, 1997)

Notes and References

1. Web site: NASA/IPAC Extragalactic Database . Results for NGC 6251 . 2006-10-26 .
2. Web site: Distance and Length . Online-Unit-Converter.com . 2010-03-29 . dead . https://web.archive.org/web/20100330094009/http://www.online-unit-converter.com/distance-and-length/ . 2010-03-30.
3. http://simbad.u-strasbg.fr/simbad/sim-id?protocol=html&Ident=QSO+B1637%2B826 SIMBAD
4. 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. 10.1086/190931 . 1984ApJS...54..291P.