ON THE ELLIPTICITIES OF YOUNG MASSIVE CLUSTERS IN M31

The projected ellipticities and orientations of 11 young massive clust ers in the Andromeda galaxy have been determined by using isodensity c ontours and 2D Gaussian fitting techniques. One to five B plates taken with the 2 m Ritchey-Chretien reflector of the Bulgarian National Ast ronomical Observatory were digitized and processed for each blue clust er. The derived ellipticities show that the blue massive disk clusters are significantly more flattened than the true globulars in M 31. The re is a statistically significant difference between the frequency dis tributions of the ellipticities of blue clusters and true globulars. A ccording to the evolutionary scenario of Shapiro and Marchant (1976) t his means that the blue massive clusters are dynamically younger than the others. There seems to be a tendency of grouping of the blue clust ers in two relatively compact regions along the spirals of M 31, very close to the star forming regions observed there.