NGC 6087
| NGC 6087 | |
|---|---|
| Observation data (J2000 epoch) | |
| Right ascension | 16h 18m 48s |
| Declination | −57° 56′ |
| Distance | ~3500LY (~1000pc) |
| Apparent magnitude (V) | 5.4 |
| Apparent dimensions (V) | 12′ |
| Physical characteristics | |
| Other designations | S Normae Cluster, Caldwell 89, Cr 300 |
| Associations | |
| Constellation | Norma |
NGC 6087 (also known as Caldwell 89 or the S Normae Cluster) 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.