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NGC 1140

Irregular galaxy in Eridanus

NGC 1140
NGC 1140, imaged by the Hubble Space Telescope
Observation data (J2000 epoch)
Constellation	Eridanus
Right ascension	02h54m 33.542s[1]
Declination	−10° 01′ 42.60″[1]
Redshift	0.005007[2]
Heliocentric radial velocity	1150 km/s[2]
Distance	59.47 ± 4.18 Mly (18.233 ± 1.283 Mpc)[2]
Apparent magnitude (V)	12.25[2]
Apparent magnitude (B)	12.84[3]
Absolute magnitude (V)	−19.05[2]
Characteristics
Type	IBm pec[2]
Apparent size (V)	1.7′ × 0.9′[2]
Notable features	Wolf–Rayet galaxy
Other designations
Markarian 1063, VV 482, MCG-02-08-019, PGC 10966[3]

NGC 1140 is an irregular galaxy in the southern constellationofEridanus. Estimates made using the Tully–Fisher method put the galaxy at about 59 million light years (18megaparsecs).^[2] It was discovered on 22 November 1786 by William Herschel, and was described as "pretty bright, small, round, stellar" by John Louis Emil Dreyer, the compiler of the New General Catalogue.^[4]

NGC 1140 is a starburst galaxy, meaning it is forming stars at a very fast rate. In fact, while it is only a tenth as wide as the Milky Way, it is producing stars at a rate of 0.65 M_☉/yr,^[5] about the same as the Milky Way. The image taken by the Hubble Space Telescope shows bright blue and red regions of star formation, similar to NGC 1569.^[6] The starburst is estimated to have begun about 5 million years ago.^[5] Its low metallicity (the ratio of hydrogen and helium to other elements) makes NGC 1140 similar to primordial galaxies.^[6]

Wolf–Rayet stars, a class of blue, massive, and luminous stars, are present in this galaxy; in fact, NGC 1140 has so many of them that their spectra also appear in the galaxy's spectrum.^[5] These types of galaxies are known Wolf–Rayet galaxies, and are fairly rare because Wolf–Rayet stars are a short stage in the lives of very massive stars.^[7]

• 
  NGC 1140 by GALEX
• 
  DSS image of NGC 1140
• 
  Pan-STARRS image of NGC 1140

• Media related to NGC 1140 at Wikimedia Commons