Talk

From slow to fast type rotators in NGC 2516 and NGC 3532

Dario Fritzewski, AIP

Young open clusters contain both slow and fast rotators while older clusters are populated exclusively by slow rotators. Many questions on the transition from fast to slow type rotators are still open. With new observation we aim to enhance the knowledge about this transition, which takes place, for G and K type stars, between ~120 and ~400 Myr. We have observed the two very rich, souther open clusters NGC 2516 (150 Myr) and NGC 3532 (300 Myr) and present a large number of new rotation period measurements for them. Based on our homogeneous photometry for both clusters we compare the distribution of rotation periods in detail and study the rotational evolution over this important age range. Further, we compare NGC 2516 with the similarly aged Pleiades and find little evidence for cluster to cluster variation of the rotation period distribution.