Leo Triplet Explained

The Leo Triplet (also known as the M66 Group) is a small group of galaxies about 35 million light-years away^[1] 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,^[2] the Lyons Groups of Galaxies (LGG) Catalog, and the group lists created from the Nearby Optical Galaxy sample of Giuricin et al.

Member list

Members of the Leo Triplet

Name	Type^[3]	R.A. (J2000)	Dec. (J2000)	Redshift (km/s)	Apparent Magnitude
M65	SAB(rs)a			807 ± 3	9.3^[4]
M66	SAB(s)b			727 ± 3	8.9^[5]
NGC 3628	SAb pec			843 ± 1	9.5^[6]

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.^[7] These two groups may actually be separate parts of a much larger group,and some group identification algorithms actually identify the Leo Triplet as part of the M96 Group.^[8]

See also

• NGC 5866 Group – another small group of galaxies

External links

• The Leo Triplett (M66 group) at messier.seds.org
  • Web site: M65 – Spiral Galaxy. Deep Sky Videos. Brady Haran. Szymanek, Nik. Nik Szymanek. Gray, Meghan .
• Finder chart at freestarcharts.com (PDF format)

Notes and References

1. http://www.eso.org/public/news/eso1126/ VST Looks at the Leo Triplet — and Beyond
2. Book: R. B. Tully . 1988 . Nearby Galaxies Catalog . . Cambridge . 0-521-35299-1.
3. Web site: NASA/IPAC Extragalactic Database . Results for various galaxies . 2006-10-24.
4. Web site: Messier 65 . 25 April 2022 . SEDS Messier Catalog.
5. Web site: Messier 66 . 25 April 2022 . SEDS Messier Catalog.
6. Web site: NGC 3628 . 25 April 2022 . SEDS NGC Catalog.
7. 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 . 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 . Astrophysical Journal Supplement . 2000 . 128 . 2 . 431–459 . 2000ApJS..128..431F . 10.1086/313391. astro-ph/9910501 . Kennicutt . 121612286 .
8. P. Fouque, E. Gourgoulhon, P. Chamaraux, G. Paturel . Groups of galaxies within 80 Mpc. II – The catalogue of groups and group members . Astronomy and Astrophysics Supplement . 1992 . 93 . 211–233 . 1992A&AS...93..211F . Gourgoulhon . Chamaraux . Paturel.