NGC 6087

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NGC 6087
Observation data (J2000 epoch)
Constellation Norma
Right ascension 16h 18m 48s[1]
Declination −57° 56[1]
Distance ~3500LY (~1000pc)
Apparent magnitude (V) 5.4
Apparent dimensions (V) 12
Physical characteristics
Other designations Caldwell 89

'NGC 6087 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.

References

  1. 1.0 1.1 "SIMBAD Astronomical Database". Results for NGC 6087. 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. 3.0 3.1 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. 

External links

Coordinates: 16h 18m 48s, −57° 56′ 00″

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