NGC 6087

{{Short description|Open cluster in the constellation Norma}}

{{Infobox open cluster

| image = NGC 6087 full.png

| name = NGC 6087

| type = Open Cluster

| epoch = J2000

| ra = {{RA|16|18|48}}{{cite simbad

| title=NGC 6087

| access-date=2007-04-18}}

| dec = {{DEC|-57|56}}

| dist_ly = ~3500LY

| dist_pc = ~1000pc

| appmag_v = 5.4

| size_v = 12{{prime}}

| radius_ly =

| absmag_v =

| constellation = Norma

| notes =

| names = S Normae Cluster, Caldwell 89, Cr 300

}}

File:NGC 6087 map.png

NGC 6087 (also known as Caldwell 89 or the S Normae Cluster) is an open cluster of 40 or moreBurnham'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. 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,{{cite journal

|author=A. U. Landolt

|year=1964

|title=The Galactic Cluster NGC 6087

|journal=Astrophysical Journal Supplement

|volume=8

|pages=329–351

|bibcode = 1964ApJS....8..329L |doi = 10.1086/190092 |doi-access=free

}} and the period/luminosity relationship of Cepheid variables allows the distance to be determined with confidence.