I Zwicky 18

I Zwicky 18
Hubble Space Telescope (HST) image of I Zwicky 18
Credit: HST/NASA/ESA
Observation data (J2000 epoch)
ConstellationUrsa Major
Right ascension09h 34m 02.0s
Declination+55° 14′ 28″
Redshift0.002585
Heliocentric radial velocity774 km/s
Distance60.137 ± 13.604 Mly (18.438 ± 4.171 Mpc)
Apparent magnitude (V)15.98
Characteristics
TypecI;Blue Compact Gal, WR, and AGN
Size5,150 ly × 3,650 ly
(1.58 kpc × 1.12 kpc)
(diameter; 25.0 B-mag arcsec−2)
Apparent size (V)2.0 × 2.0
Other designations
I ZW 018, 2MASS J09340202+5514272, UGCA 166, LEDA 27182, Mrk 116, PGC 27182, SDSS J093401.92+551427.9

I Zwicky 18 is a blue compact dwarf and Wolf–Rayet galaxy located about 18.44 megaparsecs (60.14 million light-years) away in the constellation Ursa Major. The galaxy was first identified by Swiss astronomer Fritz Zwicky in a 1930s photographic survey of galaxies. It also possesses an active galactic nucleus.