Massive stars in globular clusters: drivers of chemical and dynamical evolution

Massive stars have a strong impact on globular cluster evolution. First providing they rotate initially fast enough they can reach the break-up velocity during the main sequence and a mechanical mass-loss will eject matter from the equator at low velocity. Rotation-induced mixing will also bring matter from the convective core to the surface. From this ejected matter loaded in H-burning material a second generation of stars will born. The chemical pattern of these second generation stars are similar to the one observed for stars in globular cluster with abundance anomalies in light elements. Then during the explosion as supernovae the massive stars will also clear the cluster of the remaining gas. If this gas expulsion process acts on short timescale it can strongly modify the dynamical properties of clusters by ejecting preferentially first generation stars.