The Convergence Age of the Globular Cluster NGC 6397
NGC 6397 was imaged with HST/ACS for a total of 126 orbits. The imaging was done in two filters, F606W and F814W. With proper motion cleaning from archival WFPC2 data, we have constructed a color-magnitude diagram for this cluster which reaches to unprecedented depth. In particular, we have detected a truncation in the white dwarf cooling sequence and what appears to be the termination of the hydrogen-burning main sequence. This has allowed us to determine the cluster age by two largely independent techniques, from the main sequence turnoff and from the cooling white dwarfs. We present these ages and compare them with ages of other globular clusters, the age of the Universe, and the white dwarf cooling age of the Galactic thin disk.
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 2006