Cornish, Alexis S. M.; Phelps, Randy L.; Briley, Michael M.; Friel, Eileen D.
“CCD Photometry of the Globular Cluster ESO 452-SC11”
The globular cluster ESO 452-SC11 has been observed using Johnson V and Cousins I filters, and point-spread function photometry has been performed. The resulting color-magnitude diagrams were compared to theoretical isochrones to derive the cluster’s age, overall chemical composition, and distance modulus. These isochrone models include those published by Girardi et al. and Bergbusch & VandenBerg, with BVRI color-Teff relations as described by VandenBerg & Clem, and Demarque et al. (known as the Yale isochrones). From the Yale isochrones, it is estimated that the cluster has an age of 9-11 Gyr, a metallicity -1.4 dex
The Astronomical Journal, Volume 131, Issue 5, pp. 2543-2550