Constellation Norma Declination −57° 56′ Apparent magnitude (V) 5.4 | Right ascension 16 18 48 Distance ~3500LY (~1000pc) Apparent dimensions (V) 12′ | |
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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.
References
NGC 6087 Wikipedia(Text) CC BY-SA