Pegasus Dwarf Irregular Galaxy

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Pegasus Dwarf Irregular Galaxy
Observation data (J2000 epoch)
Constellation Pegasus
Right ascension 23h 28m 36.2s[1]
Declination +14° 44′ 35″[1]
Redshift -183 ± 0 km/s[1]
Distance 3.0 ± 0.1 Mly (920 ± 30 kpc)[2]
Type dIrr/dSph[1][a]
Apparent dimensions (V) 5′.0 × 2′.7[1]
Apparent magnitude (V) 13.2[1]
Other designations
UGC 12613,[1] PGC 71538,[1] DDO 216,[1] Pegasus Dwarf,[1] PegDIG[1]
See also: Galaxy, List of galaxies

The Pegasus Dwarf Irregular Galaxy (also known as Peg DIG or the Pegasus Dwarf) is an irregular galaxy and a dwarf galaxy in the direction of the constellation Pegasus. It was discovered by A.G. Wilson in the 1950s. The Pegasus Dwarf is a companion of the Andromeda Galaxy in the Local Group.

Contents

[edit] General information

In 1975 Tully & Fisher determined that it was part of the Local Group.[citation needed] The metallicity and the related distance estimate has been subject to discussions in the scientific literature, with varying results, however, recently, by use of the tip of the red giant branch, a distance within 10% error was achieved in 2000[3][4] and then improved to 3% in 2005.[2]

Location of Pegasus Dwarf in the Local Group.
Location of Pegasus Dwarf in the Local Group.

[edit] See also

[edit] Notes

  1. ^ NED gives the galaxy classification as both dIrr and dSph, which means that it is a transitory between dwarf irregular and dwarf spheroidal. It is noted as transitory in Cole et al 1999.[5]

[edit] References

  1. ^ a b c d e f g h i j k NASA/IPAC Extragalactic Database. Results for PegDIG. Retrieved on 2007-03-15.
  2. ^ a b McConnachie, A. W.; Irwin, M. J.; Ferguson, A. M. N.; Ibata, R. A.; Lewis, G. F.; Tanvir, N. (2005). "Distances and metallicities for 17 Local Group galaxies". Monthly Notices of the Royal Astronomical Society 356 (4): 979-997. doi:10.1111/j.1365-2966.2004.08514.x. 
  3. ^ Karachentsev, Igor D.; Karachentseva, Valentina E.; Huchtmeier, Walter K.; Makarov, Dmitry I. (2004). "A Catalog of Neighboring Galaxies". The Astronomical Journal 127 (4): 2031-2068. doi:10.1086/382905. 
  4. ^ van den Bergh, Sidney (2000). The Galaxies of the Local Group. Cambridge, UK: Cambridge University Press. ISBN 0521651816. 
  5. ^ Cole, Andrew A.; Tolstoy, Eline; Gallagher, John S., III; Hoessel, John G.; Mould, Jeremy R.; Holtzman, Jon A.; Saha, Abhijit; Ballester, Gilda E.; Burrows, Christopher J.; Clarke, John T.; Crisp, David; Griffiths, Richard E.; Grillmair, Carl J.; Hester, Jeff J.; Krist, John E.; Meadows, Vikki; Scowen, Paul A.; Stapelfeldt, Karl R.; Trauger, John T.; Watson, Alan M.; Westphal, James R. (1999). "Stellar Populations at the Center of IC 1613". The Astronomical Journal 118 (4): 1657-1670. doi:10.1086/301042.