NGC 581

Number of stars per data source

	Reference    1 :  350 stars
	Reference    2 :   62 stars
	Reference    7 :   62 stars
	Reference  117 :  225 stars

1: Moffat A.F.J., Vogt N.; (1974) Veroeff. Astron. Inst. Bochum no 2; Photographische UBV-helligkeiten in 14 jungen Sternhaufen der nordlichen Milchstrasse; 1974VeBoc...2....1M
2: Hoag A.A., Johnson H.L., Iriarte B., Mitchell R.I., Hallam K.L., Sharpless S.; (1961) Publ. Us. Nav. Obs. XVII part VII, 347; Photometry of stars in galactic cluster fields
7: McCuskey S.W., Houk N.; (1964) Astron. J. 69, 412; Galactic structure in Cassiopeia; 1964AJ.....69..412M
117: Osman A.M.I., Khalil A.A., Aiad A., Marie M.; (1983) J. Astron. Soc. Egypt 4, 1; UBV photometric investigation for the young open star cluster NGC 581 (M 103); 1983JASEg...4....1O