The Galaxies of the Local Group

The local group is probably a typical group of galaxies. It consists of three large spiral galaxies surrounded by numerous dwarf galaxies. Very few of the smallest type of dwarf galaxies have ever been seen in any of the neighbouring galaxy groups, they are just too dim to be seen easily. Below are all the local group galaxies known at the beginning of 2007.

Local Group Galaxies

          1               2       3        4         5       6           7             8
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   Name of Galaxy     | Galactic coords|Distance |Diameter| Galaxy   | Other      | Year of
                      |   l°      b°   |  (kly)  |  (kly) |  Type    | Name       |Discovery
--------------------------------------------------------------------------------------------
Milky Way                 0       0        0        90     SBbc                     prehist.
Sagittarius Dwarf         5.6   -14.1     78±7      20     dSph                      1994
Ursa Major II           152.5   +37.4    100±15      1     dSph                      2006
Coma Berenices Dwarf    241.9   +83.6    144±13      1     dSph                      2006
Large Magellanic Cloud  280.5   -32.9    165±5      25     SBm         ESO 56-115   prehist.
Small Magellanic Cloud  302.8   -44.3    195±15     15     SBm         NGC 292      prehist.
Boötes Dwarf            358.0   +69.6    197±9       2     dSph                      2006
Ursa Minor Dwarf        105.0   +44.8    215±10      2     dSph        DDO 199       1954
Sculptor Dwarf          287.5   -83.2    258±13      3     dSph        ESO 351-30    1937
Draco Dwarf              86.4   +34.7    267±20      2     dSph        DDO 208       1954
Sextans Dwarf           243.4   +42.2    280±13      3     dSph        PGC 88608     1990
Ursa Major I            159.4   +54.4    325?        3?    dSph                      2005
Carina Dwarf            260.1   -22.2    329±16      2     dSph        PGC 19441     1977
Fornax Dwarf            237.1   -65.7    450±26      5     dSph        ESO 356-04    1938
Hercules Dwarf           28.7   +36.9    457±41      4     dSph                      2006
Canes Venatici II       113.6   +82.7    489±46      2     dSph                      2006
Leo IV                  265.4   +56.5    522±47      2     dSph                      2006
Leo II                  220.2   +67.2    669±39      3     dSph        DDO 93        1950
Canes Venatici I         74.3   +79.8    718±82      6     dSph                      2006
Leo I                   226.0   +49.1    815±100     3     dSph        DDO 74        1950
Leo T                   214.9   +43.7   1360±65      2     dIrr/dSph                 2007
Phoenix Dwarf           272.2   -68.9   1450±100     2     dIrr/dSph   ESO 245-7     1976
NGC 6822                 25.3   -18.4   1520±85      8     Irr         DDO 209       1884
NGC 185                 120.8   -14.5   2010±60      8     dSph/dE3p   UGC 396       1787
Andromeda II            128.9   -29.2   2165±40      3     dSph        PGC 4601      1970
Leo A                   196.9   +52.4   2250±325     4     dIrr        DDO 69       c1940
IC 1613                 129.8   -60.6   2365±50     10     Irr         DDO 8        c1890
Andromeda X             125.8   -18.0   2290±120     5     dSph                      2006
NGC 147                 119.8   -14.3   2370±50     10     dSph/dE5    DDO 3        c1830
Andromeda III           119.3   -26.2   2450±50      3     dSph        PGC 2121      1970
Andromeda VII           109.5   -10.0   2465±95      2     dSph        PGC 2807155   1999
Cetus Dwarf             101.4   -72.8   2485±65      3     dSph        PGC 3097691   1999
Andromeda IX            123.2   -19.7   2505±75      4     dSph                      2004
Andromeda I             121.7   -24.9   2520±60      2     dSph        PGC 2666      1970
LGS 3                   126.8   -40.9   2520±70      2     dIrr/dSph   Pisces Dwarf  1978
Andromeda V             126.2   -15.1   2560±80      2     dSph        PGC 3097824   1998
Andromeda Galaxy, M31   121.2   -21.6   2560±50    140     Sb          NGC 224       c964
Andromeda XI            121.7   -29.1   2560±325     2     dSph                      2006
Andromeda XII           122.0   -28.5   2560±325     2     dSph                      2006
Andromeda XIII          123.0   -29.9   2560±325     2     dSph                      2006
Andromeda VI            106.1   -36.3   2595±50      3     dSph        PGC 2807158   1998
M32                     121.2   -22.0   2625±115     8     dE2         NGC 221       1749
M110                    120.7   -21.7   2690±80     15     dSph/dE5    NGC 205       1773
IC 10                   119.0    -3.3   2690±165     8     dIrr        UGC 192      c1890
Triangulum Galaxy, M33  133.6   -31.3   2735±55     55     Sc          NGC 598       1654
Tucana Dwarf            322.9   -47.4   2870±130     2     dSph        PGC 69519     1990
Pegasus Dwarf            94.8   -43.5   3000±80      6     dIrr/dSph   DDO 216         ?
WLM                      75.9   -73.6   3020±80     10     Irr         DDO 221       1909
Aquarius Dwarf           34.0   -31.3   3345±100     3     dIrr/dSph   DDO 210       1959
SagDIG                   21.1   -16.3   3460±520     3     dIrr        ESO 594-4     1977
Antlia Dwarf            263.1   +22.3   4030±210     3     dIrr/dSph   PGC 29194     1997
NGC 3109                262.1   +23.1   4075±540    25     Irr         DDO 236      c1836
Sextans A               246.2   +39.9   4350±120    10     dIrr        DDO 75          ?
Sextans B               233.2   +43.8   4385±325     8     dIrr        DDO 70          ?
Column 1: The most common name of the galaxy.
Column 2: The galactic longitude of the galaxy.
Column 3: The galactic latitude of the galaxy.
Column 4: The distance to the galaxy in thousands of light years together with
          the approximate error in the distance.
Column 5: The diameter of the galaxy in thousands of light years.  For dwarf
          galaxies this is only very approximate.
Column 6: The standard classification of the galaxy.
Column 7: Alternative catalogue name for the galaxy.
Column 8: Year the galaxy was discovered.

References:
Mateo M, (1998), Dwarf Galaxies of the Local Group. Annu Rev Astron Astrophys 36, 435.
van den Bergh S, (2000), Updated Information on the Local Group. Publications of the Astron
   Soc of the Pacific, 112, 529.
McConnachie A, Irwin M, Ferguson A, Ibata R, Lewis G, Tanvir N, (2005), Distances and
   Metallicities for 17 Local Group Galaxies. Monthly Notices of the Royal Astron Soc, 356, 979.
Zucker, Kniazev, Bell, Martínez-Delgado, Grebel, Rix, Rockosi, Holtzman, Walterbos, Annis, York,
   Ivezić, Brinkmann, Brewington, Harvanek, Hennessy, Kleinman, Krzesinski, Long, Newman, Nitta,
   Snedden, (2004), Andromeda IX: A New Dwarf Spheroidal Satellite of M31. Astrophys J, 612, L121
Willman, Dalcanton, Martinez-Delgado, West, Blanton, Hogg, Barentine, Brewington, Harvanek,
   Kleinman, Krzesinski, Long, Neilsen, Nitta, Snedden, (2005), A New Milky Way Dwarf Galaxy
   in Ursa Major. Astrophys J, 626, L85.
Zucker, Kniazev, Martínez-Delgado, Bell, Rix, Grebel, Holtzman, Walterbos, Rockosi, York,
   Barentine, Brewington, Brinkmann, Harvanek, Kleinman, Krzesinski, Long, Neilsen, Nitta,
   Snedden, (2007), Andromeda X, A New Dwarf Spheroidal Satellite of M31. Astrophys J, 659, L21.
Zucker, Belokurov, Evans, Wilkinson, Irwin, Sivarani, Hodgkin, Bramich, Irwin, Gilmore, Willman,
   Vidrih, Fellhauer, Hewett, Beers, Bell, Grebel, Schneider, Newberg, Wyse, Rockosi, Yanny,
   Lupton, Smith, Barentine, Brewington, Brinkmann, Harvanek, Kleinman, Krzesinski, Long, Nitta,
   Snedden, (2006), A New Milky Way Dwarf Satellite in Canes Venatici. Astrophys J, 643, L103.
Belokurov, Zucker, Evans, Wilkinson, Irwin, Hodgkin, Bramich, Irwin, Gilmore, Willman, Vidrih,
   Newberg, Wyse, Fellhauer, Hewett, Cole, Bell, Beers, Rockosi, Yanny, Grebel, Schneider,
   Lupton, Barentine, Brewington, Brinkmann, Harvanek, Kleinman, Krzesinski, Long, Nitta, Smith,
   Snedden, (2006), A Faint New Milky Way Satellite in Bootes. Astrophys J, 647, L111.
Zucker, Belokurov, Evans, Kleyna, Irwin, Wilkinson, Fellhauer, Bramich, Gilmore, Newberg, Yanny,
   Smith, Hewett, Bell, Rix, Gnedin, Vidrih, Wyse, Willman, Grebel, Schneider, Beers, Kniazev,
   Barentine, Brewington, Brinkmann, Harvanek, Kleinman, Krzesinski, Long, Nitta, Snedden,
   (2006), A Curious New Milky Way Satellite in Ursa Major. Astrophys J, 650, L41.
Martin, Ibata, Irwin, Chapman, Lewis, Ferguson, Tanvir, McConnachie, (2006), Discovery and
   analysis of three faint dwarf galaxies and a globular cluster in the outer halo of the
   Andromeda galaxy. Monthly Notices Royal Astron Soc, 371, 1983.
Belokurov, Zucker, Evans, Kleyna, Koposov, Hodgkin, Irwin, Gilmore, Wilkinson, Fellhauer,
   Bramich, Hewett, Vidrih, De Jong, Smith, Rix, Bell, Wyse, Newberg, Mayeur, Yanny, Rockosi,
   Gnedin, Schneider, Beers, Barentine, Brewington, Brinkmann, Harvanek, Kleinman, Krzesinski,
   Long, Nitta, Snedden, (2007), Cats and Dogs, Hair and A Hero: A Quintet of New Milky Way
   Companions. Astrophys J, 654, 897.
Irwin, Belokurov, Evans, Ryan-Weber, de Jong, Koposov, Zucker, Hodgkin, Gilmore, Prema, Hebb,
   Begum, Fellhauer, Hewett, Kennicutt, Wilkinson, Bramich, Vidrih, Rix, Beers, Barentine,
   Brewington, Harvanek, Krzesinski, Long, Nitta, Snedden, (2007), Discovery of an Unusual
   Dwarf Galaxy in the Outskirts of the Milky Way. Astrophys J, 656, L13.

Galaxy Remnants

These are some disrupted galaxies which are sometimes listed as Local Group Galaxies. The Canis Major Dwarf is (possibly) a remnant of a dwarf galaxy lying within the Milky Way. Andromeda VIII is the disrupted remains of a galaxy in front of the Andromeda Galaxy.

          1               2       3        4         5       6           7             8
____________________________________________________________________________________________
   Name of Galaxy     | Galactic coords|Distance |Diameter| Galaxy   | Other      | Year of
                      |   l°      b°   |  (kly)  |  (kly) |  Type    | Name       |Discovery
--------------------------------------------------------------------------------------------
Canis Major Dwarf       244.0    -6.0     24±3      20     dIrr?                     2003
Andromeda VIII          121.0   -22.2   2500±200    30     dSph                      2003
References:
Morrison H, Harding P, Hurley-Keller D, Jacoby G, (2003), Andromeda VIII - a New Tidally
   Distorted Satellite of M31. Astrophys J, 596, L183.
Bellazzini M, Ibata R, Martin N, Lewis G, Conn B, Irwin M, (2006), The core of the Canis Major
   galaxy as traced by red clump stars.  Monthly Notices of the Royal Astron Soc, 366, 865.

Digitized Sky Survey image
The Andromeda Galaxy - the largest galaxy in the local group. Also visible are two of its satellite galaxies, M32 (left) and M110 (bottom right.)
The local group Back to the Local Group page