Globular Cluster Ages from Main Sequence Fitting and Detached, Eclipsing Binaries: The Case of 47 Tuc

Age constraints are most often placed on globular clusters by comparing their CMDs with theoretical isochrones. The recent discoveries of detached, eclipsing binaries in such systems by the Cluster AgeS Experiment (CASE) provide new insights into their ages and, at the same time, much needed tests of stellar evolution models. We describe efforts to model the properties of the detached, eclipsing binary V69 in 47 Tuc and compare age constraints derived from stellar evolution models of V69A and B with ages obtained from fitting isochrones to the cluster CMD. We determine, under reasonable assumptions of distance, reddening, and metallicity, the extent to which it is possible to simultaneously constrain the age and He content of 47 Tuc.

10 pages, 5 figures (some bitmapped), full res version available from http://www.astro.uvic.ca/~dotter/IAU258/paper_fullres.ps; to appear in Proceedings of IAU Symposium 258: The Ages of Stars