NGC 7793 is a flocculent spiral galaxy in the southern constellation of Sculptor. It was discovered on July 14, 1826, by Scottish astronomer James Dunlop. The galaxy is located at a distance of million light years and is receding with a heliocentric radial velocity of .
NGC 7793 is one of the five brightest galaxies within the Sculptor Group. It is once thought to part of a group known as LGG 4, which has 7 core members, which are NGC 55, NGC 300, ESO 349-31, ESO 351-30, ESO 295-29 and ESO 352-2.
The morphological class of NGC 7793 is SA(s)d, indicating it is unbarred spiral galaxy (SA) with no inner ring structure (s) and the arms are loosely wound and disorganized (d). It is flocculent in appearance with a very small bulge and a star cluster at the nucleus. The galactic disk is inclined at an angle of 53.7° to the line of sight from the Earth. The visible profile is elliptical in form with an angular size of and a major axis aligned along a position angle of 99.3°. There are two nearby dwarf galaxy companions.
NGC 7793 hosts the ultra-luminous X-ray pulsar (ULXP) referred to as NGC 7793 P13 (previously believed to harbor a black hole), which consists of a 0.42-second pulsar in a 64-day orbit with a 18–23 solar mass B9Ia companion star.
Supernova One supernova has been observed in NGC 7793. SN 2008bk (Type II-P, mag. 12.6) was discovered by Berto Monard (bio-it) on March 25, 2008. It reached apparent magnitude 12.5, making it the second-brightest supernova of 2008. The progenitor of this supernova was a red supergiant, observed only 547 days prior to the explosion.
Gallery
See also List of NGC objects (7001–7840) NGC 300 – a similar spiral galaxy that is near NGC 7793 NGC 2403 – a similar spiral galaxy
References
External links
SST: NGC 7793 __NOTOC__