Leo Triplet

Not to be confused with Leo Cluster or Leo I Group.

The Leo Triplet (also known as the M66 Group) is a small group of galaxies about 35 million light-years away^[5] in the constellation Leo. This galaxy group consists of the spiral galaxies M65, M66, and NGC 3628.

Leo Triplet
The Leo Triplet, with M65 (right top), M66 (right bottom) and NGC 3628 (left). North is to the left.
Observation data (Epoch J2000)
Constellation(s)	Leo
Right ascension	11h 17m[1][2]
Declination	+13° 25′[1][2]
Brightest member	M66[1][2]
Number of galaxies	3-5[1][2][3]
Other designations
M66 Group, Arp 317,[4] LGG 231,[1] NOGG P1 533,[2] NOGG P2 543[2]

Members

The table below lists galaxies that have been consistently identified as group members in the Nearby Galaxies Catalog,^[3] the Lyons Groups of Galaxies (LGG) Catalog,^[1] and the group lists created from the Nearby Optical Galaxy sample of Giuricin et al.^[2]

Member list

Members of the Leo Triplet

Name	Type[6]	R.A. (J2000)[6]	Dec. (J2000)[6]	Redshift (km/s)[6]	Apparent Magnitude
M65	SAB(rs)a	11h 18m 56.0s	+13° 05′ 32″	807 ± 3	9.3[7]
M66	SAB(s)b	11h 20m 15.0s	+12° 59′ 30″	727 ± 3	8.9[8]
NGC 3628	SAb pec	11h 20m 17.0s	+13° 35′ 23″	843 ± 1	9.5[9]

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.^[10] These two groups may actually be separate parts of a much larger group,^[10] and some group identification algorithms actually identify the Leo Triplet as part of the M96 Group.^[2][11]

See also

• NGC 5866 Group – another small group of galaxies