Multiple stellar populations in Galactic globular clusters: observational evidence

Antonino P. Milone, Giampaolo Piotto, Luigi R. Bedin, Andrea Bellini, Anna F. Marino, Yazan Momany

Published 2010-12-06Version 1

An increasing number of both photometric and spectroscopic observations over the last years have shown the existence of distinct sub-populations in many Galactic globular clusters and shattered the paradigm of globulars hosting single, simple stellar populations. These multiple populations manifest themselves in a split of different evolutionary sequences in the cluster color-magnitude diagrams and in star-to-star abundance variations. In this paper we will summarize the observational scenario.