Open star clusters: Star formation and structure

Abstract

Observational evidences indicate that the formation of open star clusters has been efficient throughout the life of our Galaxy. As a consequence, we find open clusters with ages ranging from a few Myr to few Gyr. This makes open clusters natural laboratories where we can test the theory of star formation and stellar evolution. Study of young open clusters indicates that the star formation in a few clusters is non-coeval and the star formation efficiency depends on the IMF. Our work supports the existence of corona around open clusters. The coronal regions in bound open clusters are dynamically stable in the tidal forces of the Galaxy.