A CCD color-magnitude diagram for the globular cluster IC 4499

A color-magnitude diagram (CMD) based on CCD observations in B and V is presented for the Galactic globular cluster IC 4499. The CMD reaches the main-sequence turnoff and reveals a horizontal branch (HB) similar to that of M3 in morphology; however, RR Lyrae variables compose 68 percent of the HB stars in IC 4499. We find V(HB) = 17.68 +/- 0.03 mag and, after adopting a metal abundance of (Fe/H)=- 1.65 +/- 0.10, derive a reddening of E(B-V) = 0.15 +/- 0.03 using the color of the red giant branch. We show that the (B-V) color extent of the IC 4499 HB is significantly smaller than that of M3 and NGC 3201. In particular, the red HBs of these clusters appear morphologically indistinguishable, whereas the blue HBs of M3 and NGC 3201 are more extended than that of IC 4499. If this difference is due to a variation in the mass range along the blue HB, we estimate that, in the mean, stars on the blue HB of IC 4499 are at least roughly 0.02 solar mass more massive than similar stars in M3 and NGC 3201.