NGC 663

Number of stars per data source

	Reference    1 :    1 star
	Reference   25 :   32 stars
	Reference   27 :   12 stars
	Reference   50 :    1 star

References

 1

Egret D.

(1987) Priv. Comm.

Spectral types from Simbad

 25

Zug R.S.

(1933) Lick Obs. Bull. 16, 119

An investigation of color excess in galactic star clusters

 27

Clasen M.-Ch.

(1938) Astron. Nach. 264, 33

Farbenindizes in den offenen Sternhaufen NGC 1027 und IC 1805 und den Kapteynschen Eichfeldern 26, 35 und 40

1938AN....264...33C

 50

Cannon A.J., Pickering E.C.

(1918-1924), Ann. Obs. Harvard Coll. Obs. 91 to 99 and 100

Henry Draper catalogue and extension