CCD photometry of 6 globular clusters

The color-magnitude diagrams constructed from these data reach well below the horizontal branch (HB), all of which are predominantly redward of the instability strip. From these diagrams, we have measured the magnitude of the HB, the color of the red giant branch (RGB) at the level of the HB, and the magnitude difference between the HB and the RGB clump.

Using these quantities, we are able to study the metallicities and reddenings of these clusters. We also discuss the color distribution of stars on the horizontal branch for these metal-rich systems and compare them with available data for putative field disk red HB stars. There appears to be a dearth of field red HB stars having [Fe/H]~-0.5 and B-V<0.85, which are plentiful in the clusters studied here.