NGC 957

Number of stars per data source

	Reference   15 :    1 star
	Reference  173 :    1 star
	Reference 1341 :   29 stars

15: Johnson H.L., Morgan W.W.; (1955) Astrophys. J. 122, 429; Photometric and spectroscopic observations of the double cluster in Perseus; 1955ApJ...122..429J
173: Hiltner W.A.; (1956) Astrophys. J. Suppl. 2, 389; Photometric polarization and spectrographic observations of O and B Stars; 1956ApJS....2..389H
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