Bibcode
Walker, Alistair; Bono, Giuseppe; Cassisi, Santi; Monelli, Matteo; Dall'Ora, Massimo; Andreuzzi, Gloria; Stetson, Peter
Bibliographical reference
NOAO Proposal ID #2008A-0289
Advertised on:
2
2008
Citations
0
Refereed citations
0
Description
We propose to produce definitive Color-Magnitude Diagrams (CMDs) for a
small, but carefully chosen sample of galactic globular clusters, using
the Mosaic Camera on the Blanco telescope. The large field size will
enable us to efficiently cover to beyond the published tidal radius for
even the larger clusters in our sample. We will combine with available
archival HST photometry for the dense cluster cores to measure complete
star counts for the evolved populations for each cluster, and where not
available, we will provide accurate main sequence photometry, which will
allow quantification of the binary fraction and any spread due to
composition variations. We will use existing studies of the variable
star populations of each cluster to provide extra constraints on the
cluster formation and evolution scenarios, given the complex behavior
that is increasingly being found for the more massive galactic globular
clusters. The empirical results will be compared with theoretical
predictions provided by pulsational and evolutionary models, in order to
check if they can be reproduced in the framework of canonical stellar
theory or, on the contrary, one has to invoke - at least in the case of
the more massive clusters - non canonical evolutionary scenarios.