{{short description|Group of galaxies in the constellation Leo}} {{distinguish|Leo Cluster|Leo I Group}} {{Galaxy cluster | name = Leo Triplet | image = 300px | caption= The Leo Triplet, with M65 (right top), M66 (right bottom) and<br />NGC 3628 (left). North is to the left. | constellation = Leo | epoch=J2000 | ra = 11<sup>h</sup> 17<sup>m</sup><ref name="garcia1993">{{cite journal | author=A. Garcia | title=General study of group membership. II – Determination of nearby groups | journal=Astronomy and Astrophysics Supplement | date=1993 | volume=100 | pages=47–90 | bibcode=1993A&AS..100...47G}}</ref><ref name="giuricinetal2002">{{cite journal |author1=G. Giuricin |author2=C. Marinoni |author3=L. Ceriani |author4=A. Pisani | title=Nearby Optical Galaxies: Selection of the Sample and Identification of Groups | journal=Astrophysical Journal | date=2000 | volume=543 | issue=1 | pages=178–194 | bibcode=2000ApJ...543..178G | doi=10.1086/317070 |arxiv = astro-ph/0001140 |s2cid=9618325 }}</ref> | dec= +13° 25′<ref name="garcia1993" /><ref name="giuricinetal2002" /> | member_no = 3-5<ref name="garcia1993" /><ref name="giuricinetal2002" /><ref name="nbg" /> | brightest_member = M66<ref name="garcia1993" /><ref name="giuricinetal2002" /> | other_names = M66 Group, Arp 317,<ref name="arp1966">{{cite journal | author=H. Arp | title=Atlas of Peculiar Galaxies | journal=Astrophysical Journal Supplement | date=1966 | volume=14 | pages=1–20 | bibcode=1966ApJS...14....1A | doi=10.1086/190147 }}</ref> LGG 231,<ref name="garcia1993" /><br />NOGG P1 533,<ref name="giuricinetal2002" /> NOGG P2 543<ref name="giuricinetal2002" /> }} The '''Leo Triplet''' (also known as the '''M66 Group''') is a small group of galaxies about 35 million light-years away<ref>[http://www.eso.org/public/news/eso1126/ VST Looks at the Leo Triplet — and Beyond]</ref> in the constellation Leo. This galaxy group consists of the spiral galaxies M65, M66, and NGC 3628.
==Members== The table below lists galaxies that have been consistently identified as group members in the Nearby Galaxies Catalog,<ref name="nbg">{{cite book | author=R. B. Tully | date=1988 | title=Nearby Galaxies Catalog | edition= | publisher=Cambridge University Press | location=Cambridge | isbn=0-521-35299-1}}</ref> the Lyons Groups of Galaxies (LGG) Catalog,<ref name="garcia1993" /> and the group lists created from the Nearby Optical Galaxy sample of Giuricin et al.<ref name="giuricinetal2002" />
===Member list=== {| class="wikitable" style="text-align:center;" |+'''Members of the Leo Triplet''' |- ! Name ! Type<ref name="ned">{{cite web | title=NASA/IPAC Extragalactic Database | work=Results for various galaxies | url=http://nedwww.ipac.caltech.edu/ | accessdate=2006-10-24}}</ref> ! R.A. (J2000)<ref name="ned" /> ! Dec. (J2000)<ref name="ned" /> ! Redshift (km/s)<ref name="ned" /> ! Apparent Magnitude |- | M65 | SAB(rs)a | {{RA|11|18|56.0}} | {{DEC|+13|05|32}} | 807 ± 3 | 9.3<ref>{{cite web |url=http://messier.seds.org/m/m065.html |title=Messier 65 |access-date=25 April 2022 |website=SEDS Messier Catalog}}</ref> |- | M66 | SAB(s)b | {{RA|11|20|15.0}} | {{DEC|+12|59|30}} | 727 ± 3 | 8.9<ref>{{cite web |url=http://messier.seds.org/m/m066.html |title=Messier 66 |access-date=25 April 2022 |website=SEDS Messier Catalog}}</ref> |- | NGC 3628 | SAb pec | {{RA|11|20|17.0}} | {{DEC|+13|35|23}} | 843 ± 1 | 9.5<ref>{{cite web |url=http://www.messier.seds.org/xtra/ngc/n3628.html |title=NGC 3628 |access-date=25 April 2022 |website=SEDS NGC Catalog}}</ref> |- |}
Additionally, some of the references cited above indicate that one or two other nearby galaxies may be group members. NGC 3593 is frequently but not consistently identified as a member of this group.
==Nearby groups== The M96 Group is located physically near the Leo Triplet.<ref name="ferrareseetal00">{{cite journal | author=L. Ferrarese, H. C. Ford, J. Huchra, R. C. Kennicutt Jr., J. R. Mould, S. Sakai, W. L. Freedman, P. B. Stetson, B. F. Madore, B. K. Gibson, J. A. Graham, S. M. Hughes, G. D. Illingworth, D. D. Kelson, L. Macri, K. Sebo, N. A. Silbermann | title=A Database of Cepheid Distance Moduli and Tip of the Red Giant Branch, Globular Cluster Luminosity Function, Planetary Nebula Luminosity Function, and Surface Brightness Fluctuation Data Useful for Distance Determinations | journal=Astrophysical Journal Supplement | date=2000 | volume=128 | issue=2 | pages=431–459 | bibcode=2000ApJS..128..431F | doi=10.1086/313391 |arxiv = astro-ph/9910501 | last4=Kennicutt | s2cid=121612286 }}</ref> These two groups may actually be separate parts of a much larger group,<ref name="ferrareseetal00" /> and some group identification algorithms actually identify the Leo Triplet as part of the M96 Group.<ref name="giuricinetal2002" /><ref name="fouqueetal1992">{{cite journal | author=P. Fouque, E. Gourgoulhon, P. Chamaraux, G. Paturel | title=Groups of galaxies within 80 Mpc. II – The catalogue of groups and group members | journal=Astronomy and Astrophysics Supplement | date=1992 | volume=93 | pages=211–233 | bibcode=1992A&AS...93..211F | last2=Gourgoulhon | last3=Chamaraux | last4=Paturel}}</ref>
==See also== * NGC 5866 Group – another small group of galaxies
==References== {{Reflist}}
==External links== * [http://messier.seds.org/more/m066gr.html The Leo Triplett (M66 group)] at messier.seds.org * {{WikiSky|name=The Leo Triplet|z=8}} * {{cite web|title=M65 – Spiral Galaxy|url=http://www.deepskyvideos.com/videos/messier/M65.html|work=Deep Sky Videos|publisher=Brady Haran|author=Szymanek, Nik|authorlink=Nik Szymanek|author2=Gray, Meghan }} * [https://freestarcharts.com/images/Articles/Messier/Single/M66_Finder_Chart.pdf Finder chart] at freestarcharts.com (PDF format) <!-- "Creative Commons License. What that means is you are basically free to download, use and/or distribute this work for non-commercial purposes with appropriate attribution. A simple credit of "www.freestarcharts.com" is all that's required as attribution." See https://freestarcharts.com/contact -->
{{Sky|11|17|00|+|13|25|00|36000000}}
Category:Leo Triplet Category:Leo (constellation) 317