NTT-V, NTT-I AND GUNN-Z COLOR-MAGNITUDE DIAGRAMS OF LILLER-1 - A GLOBULAR-CLUSTER AS METAL-RICH AS THE INNER BULGE STELLAR POPULATION

We carried out VRI and Gunn z observations of the obscured globular cl uster Liller 1. The cluster is so reddened (Av approximate to 9.0) tha t it is at the detection limit in V. The RGB in I vs. (I-z) shows a st rong curvature. Recalling that the nearly solar metallicity globular c lusters NGC 6553 and NGC 6528 present similar blanketing effects only in the visible bandpasses, we conclude that Liller 1 is considerably m ore metal-rich than these clusters. The CMD comparison of Liller 1 wit h the inner bulge field around it (located approximate to 5 degrees fr om the nucleus), suggests that the cluster is as metallic as the most metallic fraction of this inner bulge population. Similarly deep I and z observations at approximate to 0.5 degrees away from Liller 1, at t he nominal position of Grindlay 1 do not reveal any cluster.