The asymptotic giant branch of Magellanic cloud clusters

Abstract

Thirty-nine clusters in the Magellanic Clouds have been surveyed for carbon and M-type asymptotic giant branch (AGB) stars. We identified and obtained near-infrared photometry for about 400 such stars in and around the clusters. The cluster classification scheme of Searle, Wilkinson, and Bagnuolo (SWB), which we show to be closely correlated with cluster age, is a key element in the analysis of our data. The principal results of our investigation are as follows. In a C-M diagram the cluster M stars shift steadily redward in J - K as one goes from clusters of SWB type I to VI. This is due to the increasing age of the clusters along the sequence. There are two peaks in the color distribution o..