Carbon stars in the globular clusters of the Magellanic Clouds

Among the red globular clusters of the Magellanic Clouds there are a number with giant branches which reach very red values of B--V at the tip. Results are presented of a spectroscopic survey at the tip of the giant branch in these clusters. Numerous carbon stars were found, whose luminosities place them high on the upper asymptotic giant branch (i.e., well above the first giant branch tip). It is argued that such stars can be produced only by clusters considerably younger than the globular clusters of our Galaxy. The age of the clusters is estimated at 3 billion years (within a factor of 2). Although the Magellanic Cloud globulars split into two groups by color, the existence of a number of intermediate-age clusters in the red group is consistent with a picture of continuous cluster formation in the Clouds. The consequences are discussed of the recent discovery of large numbers of carbon stars in the field of the Clouds