Cassiopeia Dwarf
| Cassiopeia Dwarf | |
|---|---|
_Hubble_WikiSky.jpg) | |
| 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] |
| Apparent magnitude (V) | 12.9[1] |
| Characteristics | |
| Type | Sph?[1] |
| Apparent size (V) | 2′.5 × 2′.0[1] |
| Notable features | satellite galaxy of the Andromeda Galaxy |
| Other designations | |
| Andromeda VII, And VII, Cas dSph, PGC 2807155, Cassiopeia Dwarf Galaxy[1][4] | |
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 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 Karachentseva)[5] in Russia and 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.
See also
References
- ^ a b c d e f g "NASA/IPAC Extragalactic Database". Results for Cassiopeia Dwarf. Retrieved 2006-11-30.
- ^ Karachentsev, I. D.; Karachentseva, V. E.; Hutchmeier, W. K.; Makarov, D. I. (2004). "A Catalog of Neighboring Galaxies". Astronomical Journal. 127 (4): 2031–2068. Bibcode:2004AJ....127.2031K. doi:10.1086/382905.
- ^ Karachentsev, I. D.; Karachentseva, V. E. (1999). "New probable companions to M 31 found on the POSS-II". Astronomy and Astrophysics. 341 (1): 355–356. Bibcode:1999A&A...341..355K.
- ^ "NAME Andromeda VII". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2010-03-06.
- ^ 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. arXiv:astro-ph/0501083. Bibcode:2005AJ....129.2232P. doi:10.1086/428372.
External links
- SEDS: Dwarf Spheroidal Galaxy Andromeda VII
- The Cassiopeia Dwarf on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
| Location | Andromeda Galaxy → Andromeda subgroup →
Local Group → Local Sheet → Virgo Supercluster → Laniakea Supercluster → Local Hole → Observable universe → Universe Each → may be read as "within" or "part of". | .jpg) |
|---|---|---|
| Satellite galaxies |
*It is uncertain whether these are companion galaxies of the Andromeda Galaxy | |
| Catalogued stars | ||
| Other | ||
