NGC 3921
| NGC 3921 | |
|---|---|
| File:Evolution in slow motion.jpg NGC 3921, imaged by the Hubble Space Telescope | |
| Observation data (J2000 epoch) | |
| Constellation | Ursa Major |
| Right ascension | 11h 51m 06.863s[1] |
| Declination | +55° 04′ 43.38″[1] |
| Redshift | 0.019667[2] |
| Heliocentric radial velocity | 5896 km/s[2] |
| Distance | 277.9 Mly (85.19 Mpc)[3] |
| Apparent magnitude (V) | 12.64[4] |
| Apparent magnitude (B) | 13.4[4] |
| Absolute magnitude (V) | −22.09[5] |
| Characteristics | |
| Type | (R')SA0/a(s) pec[2] |
| Size | 180,200 ly (55,240 pc)[2][note 1] |
| Apparent size (V) | 2.1′ × 1.3′ |
| Other designations | |
| Arp 224, UGC 6823, MGC+09-20-009, PGC 37063 | |
NGC 3921 is an interacting galaxy in the northern constellation of Ursa Major. Estimates using redshift put it at about 59 million light years (18 megaparsecs) from Earth.[3] It was discovered on 14 April 1789 by William Herschel,[6] and was described as "pretty faint, small, round" by John Louis Emil Dreyer, the compiler of the New General Catalogue.[7]
NGC 3921 is the remnant of a galaxy merger. The two progenitor galaxies are thought to have been disk galaxies that collided about 700 million years ago.[8] The image shows noticeable star formation and structures like loops, indicative of galaxies interacting.[8] Because of this, NGC 3921 was included in Halton Arp's Atlas of Peculiar Galaxies under the designation Arp 224.[4]
Being a starburst galaxy, NGC 3921 has important features. One of them is an ultraluminous X-ray source, designated X-2, with an X-ray luminosity of 8×1039 erg/s.[9] Additionally, two candidate globular clusters have been detected within NGC 3921.[5] They are both fairly young, and about half as massive as Omega Centauri, demonstrating that mergers of gas-rich galaxies can also create more metal-rich globular clusters.[5]
References
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- ^ a b c d Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
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- ^ a b c Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b c Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
Notes
[edit | edit source]- ^ POSS1 103a-O values used.
External links
[edit | edit source]- Error creating thumbnail: File missing Media related to Lua error in Module:Commons_link at line 62: attempt to index field 'wikibase' (a nil value). at Wikimedia Commons
