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]

ConstellationPegasus

Right ascension22^h 19^m 28.9^s[1]

Declination29° 23′ 30.0″^[1]

Redshift0.015738^[1]

Quick facts Observation data (J2000 epoch), Constellation ...

NGC 7253
The spiral galaxy pair NGC 7253 imaged by the Gemini North telescope
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]

Close

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.

NGC 7253 has a possible active galactic nucleus, i.e. it has a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum, with characteristics indicating that this luminosity is not produced by the stars.^[4][5]