page_title: Local Group
hierarchical_section_title: Local Group
caption_attribution_description: English: Distribution of the iron content (in logarithmic scale) in four dwarf neighbouring galaxies of the Milky Way (Sculptor, Sextans, Fornax, and Carina), shown as relative fraction, as derived from the FLAMES/VLT observations. There is a great diversity from system to system, which reflects their widely different star formation and chemical enrichment histories. There is, however, a common denominator: contrary to naive expectations, there is a dearth of stars with very low amount of iron.
context_page_description: The Local Group is the galaxy group that includes the Milky Way.
  It has a total diameter of roughly 3 megaparsecs, and a total mass of the order of 2×10¹² solar masses.
  It consists of two clusters of galaxies in a "dumbbell" shape: the Milky Way and its satellites form one lobe, and the Andromeda Galaxy and its satellites constitute the other. The two clusters are separated by about 0.8 Mpc and move towards one another with a velocity of 123 km/s. The group itself is a part of the larger Virgo Supercluster, which may be a part of the Laniakea Supercluster.
  The total number of galaxies in the Local Group is unknown as some are occluded by the Milky Way; however, at least 80 such objects are known.
  The two largest members, the Andromeda Galaxy and the Milky Way, are both spiral galaxies with masses of about 10¹² solar masses each, and each have their own system of satellite galaxies:
  The Andromeda Galaxy's satellite system consists of Messier 32, Messier 110, NGC 147, NGC 185, Andromeda I, And II, And III, And V, And VI, And VII, And VIII, And IX, And X, And XI, And XIX, And XXI and And XXII, plus several additional ultra-faint dwarf spheroidal galaxies.
context_section_description: The Local Group is the galaxy group that includes the Milky Way. 
  It has a total diameter of roughly 3 megaparsecs (9.8 Mly), and a total mass of the order of 2×10¹² solar masses (4.0×10⁴² kg).
  It consists of two clusters of galaxies in a "dumbbell" shape: the Milky Way and its satellites form one lobe, and the Andromeda Galaxy and its satellites constitute the other. The two clusters are separated by about 0.8 Mpc (2.5×10²² m) and move towards one another with a velocity of 123 km/s. The group itself is a part of the larger Virgo Supercluster, which may be a part of the Laniakea Supercluster.
  The total number of galaxies in the Local Group is unknown as some are occluded by the Milky Way; however, at least 80 such objects are known (most of which are dwarf galaxies).
  The two largest members, the Andromeda Galaxy and the Milky Way, are both spiral galaxies with masses of about 10¹² solar masses each, and each have their own system of satellite galaxies:
  The Andromeda Galaxy's satellite system consists of Messier 32 (M32), Messier 110 (M110), NGC 147, NGC 185, Andromeda I (And I), And II, And III, And V, And VI (also known as Pegasus Dwarf Spheroidal Galaxy, or Pegasus dSph), And VII (also known as Cassiopeia Dwarf Galaxy), And VIII, And IX, And X, And XI, And XIX, And XXI and And XXII, plus several additional ultra-faint dwarf spheroidal galaxies.
  The Milky Way's satellite galaxies system comprises Sagittarius Dwarf Galaxy, Large Magellanic Cloud, Small Magellanic Cloud, Canis Major Dwarf Galaxy (disputed, considered by some not a galaxy), Ursa Minor Dwarf Galaxy, Draco Dwarf Galaxy, Carina Dwarf Galaxy, Sextans Dwarf Galaxy, Sculptor Dwarf Galaxy, Fornax Dwarf Galaxy, Leo I (a dwarf galaxy), Leo II (a dwarf galaxy), and Ursa Major I Dwarf Galaxy and Ursa Major II Dwarf Galaxy, plus several additional ultra-faint dwarf spheroidal galaxies.
  The Triangulum Galaxy is the third-largest member of the Local Group, with a mass of approximately 5×10¹⁰ M☉, and is the third spiral galaxy. It is unclear whether the Triangulum Galaxy is a companion of the Andromeda Galaxy, although the two galaxies experienced a close passage 2–4 billion years ago which triggered star formation across Andromeda's disk. The Pisces Dwarf Galaxy is equidistant from the Andromeda Galaxy and the Triangulum Galaxy, so it may be a satellite of either.
  The membership of NGC 3109, with its companions Sextans A and the Antlia Dwarf Galaxy, is uncertain due to extreme distances from the center of the Local Group.
  The other members of the group are likely gravitationally secluded from these large subgroups: IC 10, IC 1613, Phoenix Dwarf Galaxy, Leo A, Tucana Dwarf Galaxy, Cetus Dwarf Galaxy, Pegasus Dwarf Irregular Galaxy, Wolf–Lundmark–Melotte, Aquarius Dwarf Galaxy, and Sagittarius Dwarf Irregular Galaxy.
caption: Distribution of the iron content (in logarithmic scale) in four neighbouring dwarf galaxies of the Milky Way
exif: {}