NGC 6520

Number of stars per data source

	Reference   32 :  322 stars
	Reference  441 : 8261 stars

32: Kjeldsen H., Frandsen S.; (1991) Astron. Astrophys. Suppl. 87, 119; Stellar photometric stability. II. Age and distances for 13 open clusters with time series observations; 1991A&AS...87..119K
441: Carraro G., Mendez R.A., May J., Mardones D.; (2005) Astron. J. 130, 635; The open cluster NGC 6520 and the nearby dark molecular cloud Barnard 86; 2005AJ....130..635C