Multiple populations in Globular Clusters from multi-wavelength HST photometry

Abstract

Recent papers, based on Hubble Space Telescope (HST) multi-wavelength photometry, have dramatically changed the traditional view of the color-magnitude diagram (CMD) of globular clusters (GCs). Appropriate combination of ultraviolet, visual, and near infrared (NIR) photometry have revealed multiple stellar populations along the entire CMD, from the bottom of the main sequence (MS) up to the the sub-giant (SGB), the red-giant branch (RGB) and even along the horizontal-branch (HB). In this paper I will use NGC2808 as a prototype to illustrate the typical features of the multiple populations in GCs and to get information on their chemical composition. Show more