Editing Stephan's Quintet (section)

===Redshift===

NGC 7320 indicates a small [[redshift]] (790&nbsp;km/s) while the other four exhibit large redshifts (near 6,600&nbsp;km/s). Since galactic redshift is proportional to distance, NGC 7320 is only a foreground projection<ref name="Molesetal1998"/> and is ~39 million light-years<ref name="Molesetal1998"/> from [[Earth]], making it a possible member of the [[NGC 7331]] group, versus the 210–340 million light-years of the other four.<ref>{{Cite web|url=http://pages.astronomy.ua.edu/gifimages/stephan.html|title=Stephan's Quintet|website=pages.astronomy.ua.edu|access-date=2019-12-24}}</ref>

[[NGC 7319]] has a type 2 [[Seyfert galaxy|Seyfert]] nucleus.

[[File:StephansQuintettIlustrated2.gif|500px|thumb|center|alt=Photo of the area of the Hubble photo, with the various galaxies labeled by NGC number|The galaxies in the vicinity of Stephan's Quintet. The rectangle indicates the area covered by the 1998–99 [[:File:StephansQuintet3.jpg|Hubble Space Telescope image]] below.]]

A sixth galaxy, NGC&nbsp;7320C, probably belongs to the Hickson association: it has a redshift similar to the Hickson galaxies, and a tidal tail appears to connect it with NGC&nbsp;7319.<ref>{{Cite web|url=https://www.noao.edu/image_gallery/html/im0414.html|title=National Optical Astronomy Observatory: Stephan's Quintet|website=www.noao.edu|access-date=2019-12-24|archive-date=2019-12-24|archive-url=https://web.archive.org/web/20191224142658/https://www.noao.edu/image_gallery/html/im0414.html|url-status=dead}}</ref>

[[File:StephansQuintet3.jpg|thumb|Detail of the quintet in a photo by [[Hubble Space Telescope]], 1998–99. Credits: [[NASA]]/[[ESA]]]]