Constraining the evolution of red supergiants with the integrated light of star clusters.

The integrated properties of young star clusters are subject to large cluster-to-cluster variations because they depend directly on small num- bers of bright stars. At ages at which red supergiants are expected to exist, these luminous but rare stars can be blamed for most of the variations. If un- resolved clusters are to be used to constrain red supergiant models, methods must be developed that take these stochastic fluctuations into account. We dis- cuss prospects and open issues in this field, based on recent work on high mass clusters in M82, and on first experiments towards a Bayesian study of cluster populations.