The Local Group
of Galaxies

Some members of the Local Group (Source)

The Milky Way is a member of a group of galaxies termed the Local Group that contains approximately 20 bright galaxies and 30 galaxies total. The largest galaxies in the local group are the spirals Andromeda (M31) and the Milky Way.

The Large Magellanic Cloud

Some Galaxies in the Local Group

The two closest galaxies to the Milky Way are called the Magellanic Clouds, which may be viewed as satellite galaxies to the Milky Way at a distance of a little less than 200,000 light years.

They are only visible in the Southern Hemisphere, but can easily be seen by the naked-eye and their brightest stars can be seen with binoculars. They are irregular galaxies and are much smaller than the Milky Way.

The Andromeda Galaxy
Two galaxies are visible to the naked-eye in the Northern Hemisphere. The Andromeda Galaxy (M31) is a great spiral galaxy much like our own at a distance of about 3 million light years (a little less than 3 Mpc). To the naked eye it is a faint fuzzy patch that appears, with binoculars, as a lens shaped object. It has two dwarf elliptical satellite galaxies visible through a small telescope.

The other galaxy of the local group that is visible to the naked eye is the spiral M33 in Triangulum at a distance comparable to that of Andromeda. It too is a spiral galaxy, but it is smaller than Andromeda and therefore is harder to see.

Some Other Nearby Groups of Galaxies

Some other nearby groups of galaxies are listed in the following table. All told, there are about 20 small groups of galaxies lying nearer to us than the Virgo rich cluster.

Some Nearby Groups of Galaxies
Group Name Number of Members Distance (Mpc)
M81 8 3.1
Sculptor 6 1.8
Centaurus 17 3.5
M101 5 7.7
M66 + M96 ~10 9.4
NGC 1023 6 9.5



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