Planetary Nebulae in Clusters

J.Köppen, A.Acker

ABSTRACT The number of planetary nebulae expected to be present in a massive (10^6 M_sun) cluster is shown to be of the order of 1 nebula per cluster of 2 Gyr age, of which a fraction (10 percent or less) might be detectable. This number is larger for younger clusters, in which one should find planetaries of Type I (rich in He and N). Thus, massive stellar clusters of different ages could aid to establish a reliable empirical relation between nebular chemical composition and the mass of the progenitor star