| Local Group |
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An assembly of galaxies to which our own Milky Way Galaxy belongs. The dominant members are the Andromeda Galaxy (M31), which is the largest and most massive, and our own Galaxy. Next in size are the spiral galaxy in Triangulum,
M33, which is a near companion of M31, and the Large Magellanic Cloud, near our Galaxy. The other members of the Local Group are small elliptical and irregular galaxies plus a number of dwarf spheroidal galaxies,
resembling isolated globular clusters. These dwarf galaxies are so faint, it is very difficult to detect them at distances greater than the Andromeda Galaxy, so the total number is unknown. The four small elliptical galaxies (NGC 221, 205, 185 and 147) are satellites of M31; the Magellanic Clouds and various dwarf galaxies are satellites of our own. Thus the Local Group does not have a central condensation, but two subgroups centred around the two most massive members. The Local Group occupies a volume of space with a radius of about 3 million light years) (1 megaparsec). The next nearest galaxies are two or three time this distance away. See also: Maffei galaxies. |