Fornax Globular 3

After subtracting the field stars from the cluster CMD, we found no evidence for an intrinsic width of the red giant branch because the scatter is only slightly wider than the photometric errors. We determine that there is an intrinsic width to the horizontal branch because the scatter is larger than the photometric errors.

After comparing our data with earlier photometry, we find 7 possible variable stars, both within and outside the instability strip, out of a total of 74 horizontal branch stars. We calculate the horizontal branch type of cluster 3 to be of intermediate color, -0.110+/-0.104, which when compared to Fornax cluster 1, having similar metallicity, suggests a second-parameter pair. Five carbon star candidates identified by Jorgensen & Jimenez (1997, Cat. <J/A+A/317/54>) are marked in the field-subtracted color-magnitude diagram.