NGC 6531
Number of stars per data source
Reference 202 : 2 stars
Reference 206 : 1 star
Reference 207 : 12 stars
Reference 999 : 2 stars
References
- 202
- Morgan W.W., Code A.D., Whitford A.E.
- (1955) Astrophys. J. Suppl. 2, 41
- Studies in galactic structure. II. Luminosity classification for 1270 blue giant stars
- 1955ApJS....2...41M
- 206
- Hiltner W.A.
- (1956) Astrophys. J. Suppl. 2, 389
- Photometric, polarization and spectrographic observations of O and B stars
- 1956ApJS....2..389H
- 207
- Hoag A.A., Applequist L.
- (1965) Astrophys. J. Suppl. 12, 215
- Distance moduli of open clusters
- 1965ApJS...12..215H
- 999
- Houk N., Cowley A.P., Smith-Moore M.
- University of Michigan (Ann Arbor) Vol 1 (1975), Vol 2 (1978), Vol 3 (1982), Vol 4 (1988), Vol 5 (1999)
- The University of Michigan Catalogue of two-dimensional Spectral Types for the HD stars
- 1975mctd.book.....H