Local Group

Local Group is a proper name referring to the group of galaxies that our galaxy, the Milky Way, is part of. The Local Group is comprised of over 30 galaxies. The gravitational center of the group is located somewhere between the Milky Way and the Andromeda Galaxy. The galaxies of the Local Group cover a 10 million light year diameter (see 1 E23 m for distance comparisons).

The two most massive members of the group are the Milky Way and the Andromeda Galaxy. These two spirals each have a system of satellite galaxies. The Milky Way's satellite system consists of Sag DEG, Large Magellanic Cloud, Small Magellanic Cloud, Ursa Minor, Draco, Carina, Sectans, Sculptor, Fornax, Leo I, Leo II and Tucana. Andromeda's system is comprised of M32, M110, NGC 147, NGC 185, And I, And II, And III and And IV. M33, the third largest galaxy in the Local Group may or may not be a companion to the Andromeda galaxy but probably has LGS 3 as a satellite. The other members of the group are gravitionally secluded from these large subgroups.

• Spiral galaxies
  • Milky Way
  • Andromeda Galaxy (M31, NGC 224) - type Sb in Andromeda
  • Triangulum Galaxy (M33, NGC 598) - type Sc in Triangulum
• Elliptical galaxies
  • M110 (NGC 205) - type E6p in Andromeda
  • M32 (NGC 221) - type E2 in Andromeda
• Irregular galaxies
  • Wolf-Lundmark-Melotte (WLM, DDO221) - type Ir+ in Cetus
  • IC 10 - type KBm or Ir+ in Cassiopeia
  • Small Magellanic Cloud (SMC, NGC 292) - SB(s)m pec in Tucana
  • Pisces Dwarf (LGS3) - type Irr in Pisces
  • IC 1513 (DDO 8) - type IAB(s)m V in Cetus
  • Phoenix Dwarf - type Irr in Phoenix
  • Large Magellanic Cloud (LMC) - type Irr/SB(s)m in Dorado
  • Leo A (Leo III) - type IBm V in Leo
  • Sextans B (DDO 70) - type Ir+IV-V in Sextans
  • NGC 3109 - type Ir+IV-V in Hydra
  • Sextans A (DDO 75) - type Ir+V in Sextans
• Dwarf elliptical galaxies[?]
  • NGC 147 (DDO 3) - type dE5 pec in Cassiopeia
  • GR 8 (DDO 155) - type Im V
  • SagDIG (Sagittarius Dwarf Irregular Galaxy) - type IB(s)m V in Sagittarius
  • Barnards Galaxy (NGC 6822) - type IB(s)m IV-V in Sagittarius
  • Aquarius Dwarf (DDO 210) - type Im V in Aquarius
  • IC 5152 - type IAB(s)m IV in Indus
  • Pegasus Dwarf (DDO 216) - type Irr in Pegasus
• Dwarf spheroidal galaxies[?]
  • Cetus Dwarf - type dSph/E4 in Cetus
  • Andromeda III - type dE2 in Andromeda
  • NGC 185 - (dE3 pec) - Cassiopeia
  • Andromeda I - type dE3 pec? in Andromeda
  • Sculptor Dwarf (E351-G30) - type dE3 in Sculptor
  • Andromeda V - type dSph in Andromeda
  • Andromeda II - type dE0 in Andromeda
  • Fornax Dwarf (E356-G04) - type dSph/E2 in Fornax
  • Carina Dwarf (E206-G220) - type dE3 in Carina
  • Antlia Dwarf - type dE3 in Antlia
  • Leo I (DDO 74) - type dE3 in Leo
  • Sextans Dwarf - type dE3 in Sextans
  • Leo II (Leo B) - type dE0 pec in Leo
  • Ursa Minor Dwarf - type dE4 in Ursa Minor
  • Draco Dwarf (DDO 208) - type dE0 pec in Draco
  • SagDEG (Sagittarius Dwarf Elliptical Galaxy) - type dSph/E7 in Sagittarius
  • Tucana Dwarf - type dE5 in Tucana
  • Cassiopeia Dwarf (Andromeda VII) - type dSph in Cassiopeia
  • Pegasus Dwarf Spheroidal Galaxy (Andromeda VI) - type dSph ? in Pegasus

• Indentification Unclear
  • Andromeda IV - Irregular Galaxy or Star Cloud (Irr?) in 1
  • UGC-A 86 (0355+66) - Irregular, Elliptical or Lenticular Galaxy (Irr, dE or S0) in Camelopardalis
  • UGC-A 92 (EGB0427+63) - Irregular or Lenticular Galaxy (Irr or S0) in Camelopardalis

• Probable non-members
  • NGC 404 - Elliptical or Lenticular Galaxy (E0 or SA(s)0- in Andromeda
  • NGC 1569 - Irregular Galaxy (Irp+ III-IV) in Camelopardalis
  • NGC 1560 (IC 2062) - Spiral Galaxy (Sd) in Camelopardalis
  • Camelopardalis A - Irregular Galaxy (Irr) in Camelopardalis
  • Argo Dwarf - Irregular Galaxy (Irr) in Carina
  • 2318-42 - Irregular Galaxy (Irr) in Grus
  • UKS 2323-326 - Irregular Galaxy (Irr) in Sculptor
  • UGC 9128 (DDO 187) - Irregular Galaxy (Irp+) in Boötes
  • Capricornus Dwarf is a Milky Way Globular Cluster formerly classified as a Dwarf Spheroidal Galaxy
  • Ursa Major Dwarf
  • Sextans C

External links:

1. The Local Group of Galaxies (http://www.seds.org/messier/more/local.html), SEDS Messier pages

See Groups and clusters of galaxies