Berkeley 9

Number of stars per data source

	Reference  510 :  486 stars
	Reference  543 : 1085 stars

510: Maciejewski G., Niedzielski A.; (2007) Astron. Astrophys. 467, 1065; CCD BV survey of 42 open clusters; 2007A&A...467.1065M
543: Lata S., Pandey A.K., Kumar B., Bhatt H., Pace G., Sharma S.; (2010) Astron. J. 139, 378; A Deep UBVRI CCD Photometry of Six Open Star Clusters in the Galactic Anticenter Region; 2010AJ....139..378L