The age determination of young clusters in the large magellanic cloud by means of integrated photometry

The relationt=t(Q), obtained from theoretical integrated colours (B-V)₀ and (U-B)₀ for Pop. I clusters, has been employed to date a group of 13 young clusters in the LMC. The comparison with the ages derived by the t.o.p. method shows that the theoretical integrated colour indices of clusters, with evolved stars in the mass range 5–15M , are systematically bluer than the observed ones.The analysis performed indicate that, in order to reconcile observed and computed colours, the maximum effective temperature of evolved stars should be suitably lowered. The hypothesis has been advanced that such changes can be obtained by the inclusion of the mass loss in the computation of evolutionary tracks.