The Leo I Group

The Leo I group is a very famous group of galaxies because it contains a lot of bright galaxies. On the right is the M96 subgroup and on the left is the M66 subgroup which are connected to each other via NGC 3489 which lies between them.

The Leo I Group

Below - three bright galaxies in the M96 subgroup. M95 (left) and M96 (centre) are both classified as barred spiral galaxies. NGC 3377 (right) is a bright elliptical galaxy.

M95 M96 NGC 3377
M95 M96 NGC 3377

Below - three more galaxies associated with the M96 subgroup. M105 (left) and NGC 3384 (centre) are two more bright elliptical galaxies. NGC 3489 (right) is a lenticular galaxy (lenticular galaxies are much flatter than elliptical galaxies) which lies inbetween the M96 and M66 subgroups.

M105 NGC 3384 NGC 3489
M105 NGC 3384 NGC 3489

The Galaxies of the Leo I Group

This is a list of the main galaxies in the Leo I group. This group contains twelve galaxies with a diameter above thirty thousand light years.

  1             2        3      4     5      6    7     8     9
Name           Equatorial      Blue  Type  Size Size   RV   Other
               Coordinates     Mag          (')  kly  km/s  Names
               RA       Dec
NGC 3239     10 25.1  +17 10   11.7  Irr    4.5   45  1078
NGC 3299     10 36.4  +12 42   14.1  SBd    1.9   20   977
PGC 31877    10 42.0  +12 20   16.8  S0     0.6    5  1116
M95          10 44.0  +11 42   10.5  SBb    7.6   75  1117  NGC 3351
M96          10 46.8  +11 49   10.1  SBa    7.8   80  1237  NGC 3368
PGC 83339    10 46.9  +13 00   17.3  Irr    1.2   10  1171
NGC 3377A    10 47.4  +14 04   14.3  SBm    1.8   20   905  UGC 5889
PGC 83341    10 47.5  +13 53   17.5  Sc     0.5    5   909
NGC 3377     10 47.7  +13 59   11.1  E      4.4   45  1026
M105         10 47.8  +12 35   10.2  E      5.1   50  1217  NGC 3379
NGC 3384     10 48.3  +12 38   10.8  E      5.4   55  1066
PGC 32348    10 48.9  +14 07   16.1  E?     0.8   10   973
UGC 5923     10 49.1  +06 55   14.1  Sa     0.9   10  1061
NGC 3412     10 50.9  +13 25   11.4  S0     3.7   40  1191
NGC 3489     11 00.3  +13 54   11.1  S0     3.5   35  1031
NGC 3593     11 14.6  +12 49   11.8  S0     5.2   55   969
M65          11 18.9  +13 06   10.2  SBa    9.1   95  1146  NGC 3623
M66          11 20.2  +13 00    9.6  SBb    8.7   90  1066  NGC 3627
NGC 3628     11 20.3  +13 35   10.3  Sb    12.9  130  1184
IC 2787      11 23.3  +13 38   16.0  Sc     0.8   10  1081
Column 1: The usual name of the galaxy.
Column 2: The Right Ascension for epoch 2000.
Column 3: The Declination for epoch 2000.
Column 4: The blue apparent magnitude of the galaxy.
Column 5: The galaxy type: E=Elliptical, S0=Lenticular, Sa,Sb,Sc,Sd=Spiral,
          SBa,SBb,SBc,SBd=Barred Spiral, Sm,SBm,Irr=Irregular.
Column 6: The angular diameter of the galaxy (arcminutes).
Column 7: The diameter of the galaxy (thousands of light years).
Column 8: The recessional velocity (km/s) of the galaxy relative to
          the cosmic microwave background.
Column 9: Other names of the galaxy.

References:
Ferguson H, Sandage A, (1990), Population studies in groups and clusters of galaxies.
        III - A catalog of galaxies in five nearby groups. Astron J, 100, 1.
Giuricin G, Marinoni C, Ceriani L, Pisani A, (2000), Nearby optical galaxies:
        selection of the sample and identification of groups. Astrophys J, 543, 178.
Garcia A, (1993), General study of group membership. II. Determination of nearby
        groups. Astron Astrophys Supp, 100, 47.
Fouqué P, Gourgoulhon E, Chamaraux P, Paturel G, (1992), Groups of Galaxies within
        80 Mpc, Astron and Astrophys Supp, 93, 211.
The HyperLeda Database, (2003).

Below - three galaxies in the M66 subgroup. NGC 3593 (left) is a lenticular galaxy with some lanes of dust near the middle of it. M65 (centre) and M66 (right) are two bright barred spiral galaxies.

NGC 3593 M65 M66
NGC 3593 M65 M66

Shown below is NGC 3628. This is a superb example of an edge-on spiral galaxy. Like most spiral galaxies, the disk of this galaxy filled is with dark clouds of dust.

NGC 3628
NGC 3628

Properties of the Leo I Group
Equatorial Coordinates RA=11h00m Dec=+13°
Galactic Coordinates l=235° b=+60°
Supergalactic Coordinates L=95° B=-25°
Distance to the centre of the group 35 million light years
Number of large galaxies in the group 12
Alternative names for the group M66/M96 Group
The Virgo Supercluster Back to the Virgo Supercluster page