NGC 581

Number of stars per data source

	Reference   86 : 4679 stars
	Reference  223 : 2134 stars

86: Phelps R.L., Janes K.A.; (1994) Astrophys. J. Suppl. 90, 31; Young open cluster as probes of the star formation process. I. An atlas of open cluster photometry; 1994ApJS...90...31P
223: Sanner J., Geffert M., Brunzendorf J., Schmoll J.; (1999) Astron. Astrophys. 349, 448; Photometric and kinematic studies of open star clusters. I. NGC 581 (M 103); 1999A&A...349..448S