NGC 21

NGC 21 (also known as NGC 29) is a spiral galaxy in the Andromeda constellation. It was discovered by German-British astronomer William Herschel on 26 November 1790. Lewis Swift observed it again in 1885, leading to its double listing in the New General Catalogue.

NGC 21
NGC 21/NGC 29 (Sloan Digital Sky Survey)
Observation data (J 2000.0 epoch)
Constellation	Andromeda
Right ascension	00h 10m 46.9s[1]
Declination	+33° 21′ 10″[1]
Redshift	0.015911[1]
Heliocentric radial velocity	4,770 ± 4 km/s[1]
Distance	234 ± 29 Mly (71.7 ± 8.9 Mpc)[2]
Apparent magnitude (V)	+12.8
Absolute magnitude (V)	-20.75[3]
Characteristics
Type	SAB(s)bc
Apparent size (V)	1.2′ × 0.59′
Other designations
IRAS 00082+3304, NGC 29, UGC 100, MCG +05-01-048, PGC 767, CGCG 499-066[1]

NGC 7831 Group

According to A.M. Garcia, NGC 21 is a member of the NGC 7831 group (also known as LGG 1), which contains at least 18 galaxies, including NGC 13, NGC 19, NGC 20, NGC 39, NGC 43, NGC 7805, NGC 7806, NGC 7819, and NGC 7836.^[4]

NGC 21 in Infrared

See also

• NGC
• List of NGC objects (1–1000)
• List of NGC objects
• Galaxy