Proceedings of the International Astronomical Union

Contributed Papers

Observations of multiple populations in star clusters

Giampaolo Piottoa1

a1 Dipartimento di Astronomia, Università di Padova, Vicolo dell'Osservatorio, 3, I-35122, Padova, Italy email:


An increasing number of photometric observations of multiple stellar populations in Galactic globular clusters is seriously challenging the paradigm of GCs hosting single, simple stellar populations. These multiple populations manifest themselves in a split of different evolutionary sequences as observed in the cluster color-magnitude diagrams. Multiple stellar populations have been identified in Galactic and Magellanic Cloud clusters. In this paper we will summarize the observational scenario.


  • globular clusters;
  • stars: horizontal-branch;
  • stellar populations;
  • techniques: photometric;
  • astrometry