| NGC 6087 | |
| Type: | Open Cluster |
| Epoch: | J2000 |
| Ra: | [1] |
| Dist Ly: | ~3500LY |
| Dist Pc: | ~1000pc |
| Appmag V: | 5.4 |
| Size V: | 12 |
| Constellation: | Norma |
| Names: | S Normae Cluster, Caldwell 89, Cr 300 |
NGC 6087 (also known as Caldwell 89 or the S Normae Cluster) is an open cluster of 40 or more[2] 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.