Astrophysics (Index)About

Local Group

(group of galaxies including the Milky Way)

The Local Group (LG) is a galaxy group of 100+ galaxies (as of 2021), that includes the Milky Way, Andromeda, Triangulum Galaxy, and a number of dwarf galaxies (generally satellite galaxies) such as Canis Major Dwarf Galaxy, Large Magellanic Cloud, Small Magellanic Cloud, Sagittarius Dwarf Irregular Galaxy, Sagittarius Dwarf Elliptical Galaxy, and Ursa Major II Dwarf. The exact number is unclear because groups of stars continue to be discovered (each year raises the count), consensus must be reached regarding whether to classify them as galaxies, and additional observations sometimes lead to changing classifications.

The Local Group's diameter is about 10 mega-light-years. It is part of the Local Sheet and the Virgo Supercluster. The Local Group galaxies are moving toward the Virgo Cluster, (i.e., there is a difference in their relative velocity and the Hubble flow) which resides at the center of the Virgo Supercluster. The movement, which is (very roughly) on the order of 100 km/s, is termed the Virgocentric flow (VCF or Virgocentric peculiar velocity).

(galaxy cluster,local)
Further reading:

Referenced by pages:
astronomical quantities
Canis Major Dwarf Galaxy
CMB anisotropies
Council of Giants
Cerro Tololo Inter-American Observatory (CTIO)
dwarf galaxy
dwarf spheroidal galaxy (dSph)
flux-weighted gravity-luminosity relationship (FGLR)
galaxy environment
galaxy group
galaxy subgroup
gas streamer
IC 342
Large Magellanic Cloud (LMC)
Local Sheet
Local Void
Local Volume (LV)
Andromeda (M31)
Triangulum Galaxy (M33)
Magellanic clouds (MC)
Milky Way
rare designator prefixes
RR Lyrae variable (RRL)
Sagittarius Dwarf Irregular Galaxy (SagDIG)
satellite galaxy
Small Magellanic Cloud (SMC)
ultra-faint dwarf galaxy (UFD)
Ursa Major II Dwarf
Virgo Cluster
Virgo Supercluster
Wolf-Lundmark-Melotte (WLM)
wind-momentum luminosity relationship (WLR)
Wolf-Rayet star