Robuta

https://commons.wikimedia.org/wiki/Category:NGC_2439 Category:NGC 2439 - Wikimedia Commons ngc 2439 category wikimedia commons https://www.aanda.org/articles/aa/abs/2002/15/aa1979/aa1979.html CCD photometric search for peculiar stars in open clusters - III. NGC 2439, NGC 3960, NGC 6134, NGC...