Local Group

The Local Group is the group of galaxies that includes Earth's galaxy, the Milky Way. The group comprises more than 54 galaxies (including dwarf galaxies), with its gravitational center located somewhere between the Milky Way and the Andromeda Galaxy. The galaxies of the Local Group cover a diameter of 10 megalight-years (3.1 megaparsecs) (see 1 E+22 m for distance comparisons) and have a binary (dumbbell) distribution. The group is estimated to have a total mass of 1.29±0.14 ×1012 M and has a velocity dispersion of 61±8 km/s. The group itself is part of the Virgo Supercluster (i.e. the Local Supercluster).

The two most massive members of the group are the Milky Way and the Andromeda Galaxy. These two spiral galaxies each have a system of satellite galaxies.

  • The Milky Way's satellite system consists of Sagittarius Dwarf Galaxy, Large Magellanic Cloud, Small Magellanic Cloud, Canis Major Dwarf, Ursa Minor Dwarf, Draco Dwarf, Carina Dwarf, Sextans Dwarf, Sculptor Dwarf, Fornax Dwarf, Leo I, Leo II, and Ursa Major I Dwarf and Ursa Major II Dwarf.
  • Andromeda's satellite system comprises M32, M110, NGC 147, NGC 185, And I, And II, And III, And IV, And V, Pegasus dSph (aka And VI), Cassiopeia Dwarf (aka And VII), And VIII, And IX, And X, And XI, And XII, And XIII, And XIV, And XV, And XVI, And XVII, And XVIII, And XIX, and And XX.
  • The Triangulum Galaxy, the third largest and only unbarred spiral galaxy in the Local Group, may or may not be a companion to the Andromeda Galaxy. Pisces Dwarf is equidistant from the Andromeda Galaxy and the Triangulum Galaxy, so it may be a satellite of either.
  • The membership of NGC 3109, and its companions Sextans A and the Antlia Dwarf, is uncertain due to their extreme distance from the center of the Local Group.

The other members of the group are gravitationally secluded from these large subgroups: IC10, IC1613, Phoenix Dwarf, Leo A, Tucana Dwarf, Cetus Dwarf, Pegasus Dwarf Irregular, Wolf-Lundmark-Melotte, Aquarius Dwarf, and Sagittarius Dwarf Irregular.

Read more about Local Group:  History, Other Notable Objects

Other articles related to "local group, group, local":

Maffei 1 - Distance
... to Maffei 1 at about 1 Mpc, which would place it within the Local Group of galaxies ... That distance puts Maffei 1 well outside the Local Group, but close enough to have influenced it in the past ... imply that Maffei 1 has never been close enough to the Local Group to significantly influence its dynamics ...
Hup People - Culture and Nuclear Family
... The married man can live, most commonly, in his father's local group or in his father-in-law's local group ... The hearth group, "kakah", is the smallest unit of production and consumption, and can be made up of a nuclear family it may also include additional persons (mothers-in-law, orphaned ... There is no ideal group size, and numbers vary enormously between one local group and another ...
Metric Expansion Of Space - Understanding The Expansion of Universe - Is The Expansion of The Universe Felt On Small Scales?
... the overall expansion, gravity causes local clumping of matter into stars and galaxies ... Within our Local Group of galaxies, the gravitational interactions have changed the inertial patterns of objects such that there is no cosmological expansion ... Once one goes beyond the local group, the inertial expansion is measurable, though systematic gravitational effects imply that larger and larger parts of space will ...

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