NGC 7253

NGC 7253 is a pair of spiral galaxies in the constellation Pegasus. It was discovered by the German-British astronomer Albert Marth on 9 September 1863.^[2] It is listed in Halton Arp's Atlas of Peculiar Galaxies as Arp 278, as an example of gravitationally interacting galaxies.^[3]

NGC 7253
The spiral galaxy pair NGC 7253 by the Pan-STARRS survey.
Observation data (J2000 epoch)
Constellation	Pegasus
Right ascension	22h 19m 28.9s[1]
Declination	29° 23′ 30.0″[1]
Redshift	0.015738[1]
Heliocentric radial velocity	4718 km/s[1]
Distance	203.7 Mly (62.46 Mpc) & 200.4 Mly (61.43 Mpc)[1]
Apparent magnitude (V)	13.2 & 14.3[1]
Characteristics
Type	Double System[1]
Size	~135,000 ly (41.40 kpc) & 71,400 ly (21.88 kpc) (estimated)[1]
Apparent size (V)	1.7' x 0.8' & 1.6' x 0.5'[1]
Other designations
Arp 278, UGC 11984 & 11985, MCG +05-52-010 & +05-52-011, PGC 68572 & 68573, CGCG 494-014, VV 242[1]

Of the pair, the galaxy to the north is known individually as NGC 7253A. Its velocity relative to the cosmic microwave background is 4,235 ± 24 km/s, which corresponds to a Hubble distance of 62.5 ± 4.4 Mpc (~204 million light-years).^[1] The other galaxy in the pair is known individually as NGC 7253B. Its velocity relative to the cosmic microwave background is 4,165 ± 24 km/s, which corresponds to a Hubble distance of 61.4 ± 4.3 Mpc (~200 million light-years).^[1]

With a surface brightness equal to 14.06 Mag/arcsec², NGC 7253B can be described as a low surface brightness galaxy.

According to the Simbad database, NGC 7253 is a candidate for the title of active galaxy nucleus.^[4]

One supernova has been observed in NGC 7253B: SN 2002jg (Type Ia, mag. 17) was discovered by Mike Schwartz and LOTOSS (Lick Observatory and Tenagra Observatory Supernova Searches) on 23 November 2002.^[5][6]

Image Gallery

• 
  NGC 7253 imaged by the Hubble Space Telescope (data processing by Judy Schmidt).

See also

• List of NGC objects (7001–7840)