Abstract

We have obtained Washington CCD photometry of NGC 5927 and NGC 6496, two globular clusters located within several kiloparsecs of the Galactic center. The data reach almost to the main-sequence turnoffs, showing well-defined giant and subgiant branches, and provide accurate photometry for more than 100 giants in each cluster. Photometry of nearby comparison fields allows us to estimate the contribution of field stars to the cluster color-magnitude diagrams. Color indices for the giants are used to determine mean cluster metallicities; we find [Fe/H] = - 0.25 +/- 0.25 for NGC 5927 and [Fe/H] = - 1.05 +/- 0.30 for NGC 6496, where the error estimates include both internal and external photometric errors, as well as uncertainties due to reduction technique. Uncertainties in the reddening to NGC 6496 have a significant impact on our ability to determine the metallicity for this cluster from color indices alone. A small increase in the reddening E(B - V) from 0.19 to 0.23 would increase the derived abundance to [Fe/H] = - 0.8, and bring it into better agreement with other abundance indicators.