Cassiopeia Dwarf

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Cassiopeia Dwarf
Observation data (J2000 epoch)
Constellation Cassiopeia
Right ascension 23h 26m 31.0s[1]
Declination +50° 41′ 31″[1]
Redshift -307 ± 2 km/s[1]
Distance 2.58 ± 0.13 Mly (790 ± 40 kpc)[2][3]
Type Sph?[1]
Apparent dimensions (V) 2′.5 × 2′.0[1]
Apparent magnitude (V) 12.9[1]
Notable features satellite galaxy of M31
Other designations
Andromeda VII[1], And VII,[4] Cas dSph,[4], PGC 2807155
Cassiopeia Dwarf Galaxy[4]
See also: Galaxy, List of galaxies

The Cassiopeia Dwarf (also known as Andromeda VII) is a dwarf spheroidal galaxy about 2.58 Mly away in the constellation Cassiopeia. The Cassiopeia Dwarf is part of the Local group of galaxies and a satellite galaxy of the Andromeda Galaxy (M31).

The Cassiopeia Dwarf was found in 1998, together with the Pegasus Dwarf, by a team of astronomers (Karachentsev and Kashibadze)[5] in Russia and the Ukraine. The Cassiopeia Dwarf and the Pegasus Dwarf are farther from M31 than its other known companion galaxies, yet still appear bound to it by gravity. Neither galaxy contains any young, massive stars or shows traces of recent star formation. Instead, both seem dominated by very old stars, with ages of up to 10 billion years.

Cassiopeia Dwarf by HST/WikiSky

[edit] See also

[edit] External links

[edit] References

  1. ^ a b c d e f g "NASA/IPAC Extragalactic Database". Results for Cassiopeia Dwarf. http://nedwww.ipac.caltech.edu/. Retrieved 2006-11-30. 
  2. ^ I. D. Karachentsev, V. E. Karachentseva, W. K. Hutchmeier, D. I. Makarov (2004). "A Catalog of Neighboring Galaxies". Astronomical Journal 127: 2031–2068. doi:10.1086/382905. http://adsabs.harvard.edu/abs/2004AJ....127.2031K. 
  3. ^ Karachentsev, I. D.; Kashibadze, O. G. (2006). "Masses of the local group and of the M81 group estimated from distortions in the local velocity field". Astrophysics 49 (1): 3–18. doi:10.1007/s10511-006-0002-6. http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2006Ap.....49....3K. 
  4. ^ a b c "SIMBAD Astronomical Database". Results for Andromeda V. http://simbad.u-strasbg.fr/Simbad. Retrieved 2006-11-30. 
  5. ^ Pritzl, Barton J.; Armandroff, Taft E.; Jacoby, George H.; Da Costa, G. S. (May 2005), "The Dwarf Spheroidal Companions to M31: Variable Stars in Andromeda I and Andromeda III", The Astronomical Journal 129 (5): 2232–2256, doi:10.1086/428372, http://adsabs.harvard.edu/abs/2005AJ....129.2232P 

Coordinates: Sky map 23h 26m 31.0s, +50° 41′ 31″


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