We report photometric features of the HB, MSTO, and SGB for a set of metal-poorGalactic globular clusters on the near-IR CMDs. The magnitude and color of theMSTO and SGB are measured on the ducial normal points of the CMDs by apply-ing a polynomial t....
We report photometric features of the HB, MSTO, and SGB for a set of metal-poorGalactic globular clusters on the near-IR CMDs. The magnitude and color of theMSTO and SGB are measured on the ducial normal points of the CMDs by apply-ing a polynomial t. The near-IR luminosity functions of horizontal branch stars inthe classical second parameter pair M3 and M13 indicate that HB stars in M13 aredominated by hot stars that are relatively faint in the infrared,whereas HB stars in M3are brighter than those in M13. The luminosity functions of HB stars in the observedbulge clusters, except for NGC 6717, show a trend that the fainter hot HB stars aredominated in the relatively metal-poor clusters while the relatively metal-rich clusterscontain the brighter HB stars. It is suggestive that NGC 6717 would be an extremeexample of the second-parameter phenomenon for the bulge globular clusters.