NGC 457

NGC 457 (also known as the Owl Cluster, the ET Cluster, or Caldwell 13) is an open star cluster in the constellation Cassiopeia. It was discovered by William Herschel in 1787,[2] and lies over 7,900 light years away from the Sun. It has an estimated age of 21 million years.[1] The cluster is sometimes referred by amateur astronomers as the Owl Cluster, Kachina Doll Cluster,[2] the ET Cluster (due to its resemblance to the movie character) or the "Skiing Cluster". Two bright stars, magnitude 5 Phi-1 Cassiopeiae and magnitude 7 Phi-2 Cassiopeiae can be imagined as eyes. The next brightest star is the red supergiant variable star V466 Cassiopeiae. The cluster features a rich field of about 150 stars of magnitudes 12-15.[2]

NGC 457
Observation data (J2000.0 epoch)
ConstellationCassiopeia
Right ascension01h 19m 32.6s
Declination+58° 17′ 27″
Distance7.922 kly (2.429[1] kpc)
Apparent magnitude (V)6.4[2]
Apparent dimensions (V)13.0′[2]
Physical characteristics
Other designationsOwl Cluster, E.T. Cluster, Caldwell 13, Cr 12, Mel 7, OCL 321, Lund 43, H VII-42, h 97, GC 256,[2]

References
  1. Frinchaboy, Peter M.; et al. (2008). "Open Clusters as Galactic Disk Tracers. I. Project Motivation, Cluster Membership, and Bulk Three-Dimensional Kinematics". The Astronomical Journal. 136 (1): 118–145. arXiv:0804.4630. Bibcode:2008AJ....136..118F. doi:10.1088/0004-6256/136/1/118. See table I, p. 12.
  2. "NGC 457". The NGC/IC Project Database. Archived from the original on 2012-05-20. Retrieved 2012-05-09.


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