NGC 884
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The Double Cluster, NGC 869 (right) and |
|
| Observation data: J2000 epoch | |
|---|---|
| Class: | - |
| Constellation: | Perseus |
| Right ascension: | 02h 22.0m[1] |
| Declination: | +57° 08′[1] |
| Distance: | 7.6 kly[2] (2.3 kpc[2]) |
| Apparent magnitude (V): | 6.1[1] |
| Apparent dimensions (V): | 30′ |
| Physical characteristics | |
| Mass: | (- M☉) |
| Radius: | - |
| VHB: | - |
| Estimated age: | 12.5 My [2] |
| Notable features: | - |
| Other designations: | Collinder 25,[1] Melotte 14,[1] |
| See also: Open cluster, List of open clusters | |
NGC 884 is an open cluster located 7600 light years[2] away in the constellation of Perseus. The cluster is most likely around 12.5[2] million years old. It is the easternmost of the Double Cluster with NGC 869. Located in the Perseus OB1 association both clusters are located physically close to one another, only a few hundred light years apart. The clusters were first recorded by Hipparchus, but have likely been known since antiquity.
The Double Cluster is a favorite of amateur astronomers. These bright clusters are often photographed or observed with small telescopes. Easy to find, the clusters are visible with the unaided eye between the constellations of Perseus and Cassiopeia as a brighter patch in the winter Milky Way.
In small telescopes the cluster appears as a beautiful assemblage of bright stars located in a rich star field. Dominated by bright blue stars the cluster also hosts a few orange stars that add to the visual interest. Both clusters together offer a spectacular low magnification view.
Sometimes known as χ Per this designation more probably refers to both clusters[3].
[edit] External links
[edit] References
- ^ a b c d e f g h i SIMBAD Astronomical Database. Results for NGC 884. Retrieved on December 22, 2006.
- ^ a b c d e N.V. Kharchenko, A.E. Piskunov, S. Röser, E. Schilbach, and R.-D. Scholz, 2005, "Astrophysical Parameters of Galactic Open Clusters", Astronomy and Astrophysics, Volume 438, Issue 3, August 2005, pp.1163-1173
- ^ Stephen James O'Meara and Daniel W.E. Green, 2003, "The Mystery of the Double Cluster", Sky and Telescope,Vol. 105, No. 2, p. 116-119 (February 2003)
