NGC 6745

NGC 6745
Irregular Galaxy NGC 6745A with NGC 6745B (bottom right)
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]
Type	S?[1]
Apparent dimensions (V)	1′.4[1]
Apparent magnitude (V)	13.3[1]
Other designations
UGC 11391,[1] PGC 62691[1], Bird's Head,[3] NGC 6745a / 6745b / 6745c[3]
See also: Galaxy, List of galaxies

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 is actually a triplet 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 (NCG 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.

The age of NGC 6745 is estimated to be ~10 Myr.^[3]

See also

• IC 1296
• Antennae Galaxies

References

1. ^ ^{a b c d e f g h} "NASA/IPAC Extragalactic Database". Results for NGC 6745. http://nedwww.ipac.caltech.edu/. Retrieved 2006-11-25. 
2. ^ "A Bird's Eye View of a Galaxy Collision - Fast Facts". http://hubblesite.org/newscenter/archive/releases/2000/34/fastfacts/. Retrieved 2008-02-26. 
3. ^ ^{a b c} de Grijs, R.; Anders, P.; Bastian, N.; Lynds, R.; Lamers, H. J. G. L. M.; O'Neil, E. J. (2003). "Star cluster formation and evolution in nearby starburst galaxies - II. Initial conditions". Monthly Notice 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. 

External links

Media related to NGC 6745 at Wikimedia Commons

• NGC 6745: The Astronomer's Story
• HubbleSite - NewsCenter - A Bird's Eye view of a Galaxy Collision
• APOD: 2006 November 5 - A Galaxy Collision in NGC 6745