NGC 6087

Coordinates: Sky map 16h 18m 48s, −57° 56′ 00″
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NGC 6087
Observation data (J2000 epoch)
Right ascension16h 18m 48s[1]
Declination−57° 56′[1]
Distance~3500LY (~1000pc)
Apparent magnitude (V)5.4
Apparent dimensions (V)12
Physical characteristics
Other designationsS Normae Cluster, Caldwell 89, Cr 300
See also: Open cluster, List of open clusters
Map showing the location of NGC 6087

NGC 6087 (also known as Caldwell 89 or the S Normae Cluster) is an open cluster of 40 or more[2][3] stars centered on the Cepheid variable S Normae in the constellation Norma. At a distance of about 3500 ly and covering a field of almost one quarter of a degree, the stars range from seventh- to eleventh-magnitude, the brightest being 6.5 magnitude S Normae. The aggregate visual magnitude of the cluster is about 5.4.

Spectral analysis of the radial motion of the stars confirm that S Normae is a member of the cluster,[3] and the period/luminosity relationship of Cepheid variables allows the distance to be determined with confidence.


  1. ^ a b "NGC 6087". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2007-04-18.
  2. ^ Burnham's Celestial Handbook gives the number 40, though other studies go as high as 349; see Stephen James O'Meara, The Caldwell Objects, Cambridge University Press, 2002, p. 351.
  3. ^ a b A. U. Landolt (1964). "The Galactic Cluster NGC 6087". Astrophysical Journal Supplement. 8: 329–351. Bibcode:1964ApJS....8..329L. doi:10.1086/190092. Retrieved 4 April 2013.

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