NGC 6745

{{Short description|Galaxy in the constellation Lyra}}

{{more footnotes|date=October 2020}}

{{Infobox Galaxy

| name = NGC 6745

| image = NGC 6745.jpg

| caption = Irregular Galaxy NGC 6745A with NGC 6745B (bottom right) imaged by the Hubble Space Telescope

| epoch = J2000

| type = S?{{cite web

| website=NASA/IPAC Extragalactic Database

| publisher = NASA and Caltech

| title=Results for object NGC 6745

| url=https://ned.ipac.caltech.edu/byname?objname=NGC+6745

| access-date=2006-11-25}}

| ra = {{RA|19|01|41.6000}}

| dec = {{DEC|+40|44|44.000}}

| dist_ly = 206 Mly{{cite web|url=http://hubblesite.org/newscenter/archive/releases/2000/34/fastfacts/|title=A Bird's Eye View of a Galaxy Collision - Fast Facts|access-date=2008-02-26}}

| z = 0.015160

| h_radial_v = {{val|4545|60|u=km/s|fmt=commas}}{{r|ned}}

| appmag_v = 13.3

| size_v = 1.4{{prime}}

| constellation name = Lyra

| names = {{ odlist | UGC= 11391 | PGC= 62691 | CGCG= 229-013 | IRAS= 19000+4040}},
Bird's Head,{{cite journal

| author=de Grijs, R.

| display-authors=4

| author2=Anders, P.

| author3=Bastian, N.

| author4=Lynds, R.

| author5=Lamers, H. J. G. L. M.

| author6=O'Neil, E. J.

| title=Star cluster formation and evolution in nearby starburst galaxies - II. Initial conditions

| journal=Monthly Notices of the Royal Astronomical Society

| date=2003

| volume=343

| issue=4

| pages=1285–1300

| bibcode=2003MNRAS.343.1285D

| doi=10.1046/j.1365-8711.2003.06777.x | doi-access=free

|arxiv = astro-ph/0305184 | s2cid=16174497

}}

NGC 6745a / 6745b / 6745c

}}

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.{{cite web | url = https://cseligman.com/text/atlas/ngc67.htm#6745 | title = New General Catalogue Objects: NGC{{nbsp}}6745 | last = Seligman | first = Courtney | website = Celestial Atlas | access-date = 28 August 2024 }}

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.