HST observations of the core of four galactic globular clusters allowed us to obtain interesting clues about the influence of the environment on the star distribution along the horizontal branch. The chemical composition and the age of the target clusters have been derived through a detailed analysis of the (V, V-I) color-magnitude diagrams. The photometric metallicities have been found in close agreement with the recent spectroscopic determinations.
Cone search capability for table J/AJ/121/916/table4a (Photometry of NGC 2298)
Cone search capability for table J/AJ/121/916/table4b (Photometry of NGC 5897)
Cone search capability for table J/AJ/121/916/table4c (Photometry of NGC 6535)
Cone search capability for table J/AJ/121/916/table4d (Photometry of NGC 6626)