Messier 65

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title: "Messier 65" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["intermediate-spiral-galaxies", "leo-triplet", "leo-(constellation)", "messier-objects", "ngc-objects", "ugc-objects", "principal-galaxies-catalogue-objects", "astronomical-objects-discovered-in-1780", "discoveries-by-charles-messier"] description: "Intermediate spiral galaxy in the constellation Leo" topic_path: "science/astronomy" source: "https://en.wikipedia.org/wiki/Messier_65" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Intermediate spiral galaxy in the constellation Leo ::

::data[format=table title="Infobox galaxy"]

Field	Value
name	Messier 65
image	[[Image:Messier 65 through the years.jpg
caption	Image taken by Hubble Space Telescope, December 30, 2013.
Credit: ESA/Hubble & NASA
epoch	J2000
constellation name	Leo
ra	{{cite web
work	NASA/IPAC Extragalactic Database
title	NED results for object MESSIER 065
url	http://ned.ipac.caltech.edu/cgi-bin/objsearch?objname=m65&extend=no&hconst=73&omegam=0.27&omegav=0.73&corr_z=1&out_csys=Equatorial&out_equinox=J2000.0&obj_sort=RA+or+Longitude&of=pre_text&zv_breaker=30000.0&list_limit=5&img_stamp=YES
access-date	2006-10-21}}
dec
size	113,500 ly (34.76 kpc) (estimated)
size_v	8.709 × 2.454 moa{{cite simbad
title	M 65
access-date	2008-07-09}}
appmag_v	9.3
type	SAB(rs)a, LINER
h_radial_v
z
gal_v
dist_ly	41-42 Mly
names	NGC 3623, UGC 6328, PGC 34612
references	SIMBAD: Search M65
::

| name = Messier 65 | image = [[Image:Messier 65 through the years.jpg|250px]] | caption = Image taken by Hubble Space Telescope, December 30, 2013. Credit: ESA/Hubble & NASA | epoch = J2000 | constellation name = Leo | ra = {{cite web | work=NASA/IPAC Extragalactic Database | title=NED results for object MESSIER 065 | url=http://ned.ipac.caltech.edu/cgi-bin/objsearch?objname=m65&extend=no&hconst=73&omegam=0.27&omegav=0.73&corr_z=1&out_csys=Equatorial&out_equinox=J2000.0&obj_sort=RA+or+Longitude&of=pre_text&zv_breaker=30000.0&list_limit=5&img_stamp=YES | access-date=2006-10-21}} | dec = | size = 113,500 ly (34.76 kpc) (estimated) | size_v = 8.709 × 2.454 moa{{cite simbad | title=M 65 | access-date=2008-07-09}} | appmag_v = 9.3 | type = SAB(rs)a, LINER | h_radial_v = | z = | gal_v = | dist_ly = 41-42 Mly | names = NGC 3623, UGC 6328, PGC 34612 | references = SIMBAD: Search M65

Messier 65 (also known as NGC 3623) is an intermediate spiral galaxy about 35 million light-years away in the constellation Leo, within its highly equatorial southern half. It was discovered by Charles Messier in 1780. With M66 and NGC 3628, it forms the Leo Triplet, a small close group of galaxies.

Discovery

M65 was discovered by Charles Messier and included in his Messier Objects list. However, William Henry Smyth accidentally attributed the discovery to Pierre Méchain in his popular 19th-century astronomical work A Cycle of Celestial Objects (stating "They [M65 and M66] were pointed out by Méchain to Messier in 1780"). This error was in turn picked up by Kenneth Glyn Jones in Messier's Nebulae and Star Clusters. This has since ramified into a number of other books by a variety of authors.

Star formation

The galaxy is low in dust and gas, and there is little star formation in it, although there has been some relatively recently in the arms. The ratio of old stars to new stars is correspondingly quite high. In most wavelengths it is quite uninteresting, though there is a radio source visible in the NVSS, offset from the core by about two arc-minutes. The identity of the source is uncertain, as it has not been identified visually, or formally studied in any published papers.

Interaction with other galaxies

To the eye, M65's disk appears slightly warped, and its relatively recent burst of star formation is also suggestive of some external disturbance. Rots (1978) suggests that the two other galaxies in the Leo Triplet interacted with each other about 800 million years ago. Recent research by Zhiyu Duan suggests that M65 may also have interacted, though much less strongly. He also notes that M65 may have a central bar—it is difficult to tell because the galaxy is seen from an oblique angle—a feature which is suggestive of tidal disruption. |author=Zhiyu Duan |year=2006 |title=Multicolor Photometry and Stellar Population Synthesis Study of the Interacting Galaxies of the Leo Triplet |journal=Astronomical Journal |volume=132 |issue=4 |pages=1581–1592 |bibcode=2006AJ....132.1581D |doi=10.1086/507304 |doi-access=free

Gallery

Messier65 - SDSS DR14.jpg|Messier 65 by the Sloan Digital Sky Survey Messier 65 Hubble WikiSky.jpg|HST image of M65 NGC3623-hst-R814GB450.jpg|M65 by Hubble Space Telescope M65 Galaxy from the Mount Lemmon SkyCenter Schulman Telescope courtesy Adam Block.jpg|M65 as imaged from the Mount Lemmon Observatory Messier 065 2MASS.jpg|Messier 65 by 2MASS

References

References

1. "Messier 65 through the years". ESA/Hubble Picture of the Week.
2. "Messier 65".
3. "Multiwavelength Messier 65".

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::