|Observation data (J2000 epoch)|
|Right ascension||16h 18m 48s|
|Apparent magnitude (V)||5.4|
|Apparent dimensions (V)||12′|
|Other designations||Caldwell 89|
NGC 6087 is an open cluster of 40 or more 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, and the period/luminosity relationship of Cepheid variables allows the distance to be determined with confidence.
- "SIMBAD Astronomical Database". Results for NGC 6087. Retrieved 2007-04-18.
- 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.
- A. U. Landolt (1964). "The Galactic Cluster NGC 6087". Astrophysical Journal Supplement 8: 329–351.
- NGC 6087 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images