NGC 6531

Number of stars per data source

	Reference  173 :    2 stars
	Reference  361 :   61 stars
	Reference 1341 :   29 stars
	Reference 1453 :    4 stars

173: Hiltner W.A.; (1956) Astrophys. J. Suppl. 2, 389; Photometric polarization and spectrographic observations of O and B Stars; 1956ApJS....2..389H
361: Forbes D.; (1996) Astron. J. 112, 1073; Star formation in NGC 6531 - Evidence from age spread and initial mass function; 1996AJ....112.1073F
1341: Hoag A.A., Johnson H.L., Iriarte B., Mitchell R.I., Hallam K.L., Sharpless S.; (1961) Publ. US. Nav. Obs. 17, 343; Photometry of stars in galactic cluster fields; 1961PUSNO..17..343H