 | This article includes a list of general references, but it lacks sufficient corresponding inline citations. (October 2020) |
| NGC 6745 | |
|---|---|
 Irregular Galaxy NGC 6745A with NGC 6745B (bottom right) imaged by the Hubble Space Telescope | |
| Observation data (J2000 epoch) | |
| Constellation | Lyra |
| Right ascension | 19h 01m 41.7s[1] |
| Declination | +40° 45′ 11″[1] |
| Redshift | 4545 ± 60 km/s[1] |
| Distance | 206 Mly[2] |
| Apparent magnitude (V) | 13.3[1] |
| Characteristics | |
| Type | S?[1] |
| Apparent size (V) | 1.4′[1] |
| Other designations | |
| UGC 11391, PGC 62691,[1] Bird's Head,[3] NGC 6745a / 6745b / 6745c[3] | |
NGC 6745 (also known as UGC 11391) is an irregular galaxy about 206 million light-years (63.5 mega-parsecs) away in the constellation Lyra. It was discovered by French astronomer Édouard Stephan on 24 July 1879.[4]
NGC 6745 is actually a trio of galaxies in the process of colliding. The three galaxies have been colliding for hundreds of millions of years. After passing through the larger galaxy (NGC 6745A), the smaller one (NGC 6745B) is now moving away. The larger galaxy was probably a spiral galaxy before the collision, but was damaged and now appears peculiar. It is unlikely that any stars in the two galaxies collided directly because of the vast distances between them. The gas, dust, and ambient magnetic fields of the galaxies, however, do interact directly in a collision. As a result of this interaction, the smaller galaxy has probably lost most of its interstellar medium to the larger one.
Four supernovae have been observed in NGC 6745: SN 1999bx (type II, mag. 16.5),[5] SN 2022prr (type IIn, mag. 17.3),[6] SN 2023ucy (type II, mag. 17.9),[7] and SN 2024ljc (type IIb, mag. 18.7).[8]
- ^ a b c d e f g "NASA/IPAC Extragalactic Database". Results for NGC 6745. Retrieved 2006-11-25.
- ^ "A Bird's Eye View of a Galaxy Collision - Fast Facts". Retrieved 2008-02-26.
- ^ a b de Grijs, R.; Anders, P.; Bastian, N.; Lynds, R.; et al. (2003). "Star cluster formation and evolution in nearby starburst galaxies - II. Initial conditions". Monthly Notices of the Royal Astronomical Society. 343 (4): 1285–1300. arXiv:astro-ph/0305184. Bibcode:2003MNRAS.343.1285D. doi:10.1046/j.1365-8711.2003.06777.x. S2CID 16174497.
- ^ Seligman, Courtney. "New General Catalogue Objects: NGC 6745". Celestial Atlas. Retrieved 28 August 2024.
- ^ Transient Name Server entry for SN 1999bx. Retrieved 24 March 2023.
- ^ Transient Name Server entry for SN 2022prr. Retrieved 24 March 2023.
- ^ Transient Name Server entry for SN 2023ucy. Retrieved 24 October 2023.
- ^ Transient Name Server entry for SN 2024ljc. Retrieved 17 June 2024.