Infrared Photometry of Metal Rich Galactic Globular Clusters

We describe the results of a program of infrared photometry using an array detector carried out at the Las Campanas Observatory on a sample of very metal rich galactic globular clusters. We have found that the giant branches of most of these clusters show a spread in various colors which is due to patchy interstellar absorption. Strong limits can be derived on the metallicity spread within these clusters by analyzing the spread of the giant branch at a given K magnitude as a function of color used