Ntt vi photometry of the metal-rich and obscured bulge globular cluster terzan 5

Abstract

We study the metal-rich bulge globular cluster Terzan 5 by means of VI colour-magnitude diagrams, with images obtained under exceptional seeing conditions (0.34"–0.50"). Differential reddening is important across the cluster. We derive a reddening of E(B – V) = 2.49 and a distance from the Sun dΘ = 5.6kpc, closer than previous estimates. Based on the red giant branch curvature, we derive a metallicity somewhat higher than that of NGC 6553, probably solar.