Powerful CMD: a tool for color-magnitude diagram studies

Abstract

We present a new tool for colour-magnitude diagram (CMD) studies,\n$Powerful~CMD$. This tool is built on the basis of the advanced stellar\npopulation synthesis (ASPS) model, in which single stars, binary stars,\nrotating stars, and star formation history have been taken into account. Via\n$Powerful~CMD$, the distance modulus, colour excess, metallicity, age, binary\nfraction, rotating star fraction, and star formation history of star clusters\ncan be determined simultaneously from observed CMDs. The new tool is tested via\nboth simulated and real star clusters. Five parameters of clusters NGC6362,\nNGC6652, NGC6838 and M67 are determined and compared to other works. It is\nshown that this tool is useful for CMD studies, in particular for those with\nthe data of the Hubble Space Telescope (HST). Moreover, we find that the\ninclusion of binaries in theoretical stellar population models may lead to\nsmaller colour excess compared to the case of single star population models.\n