The activity-rotation-age relationship in stellar clusters: NGC 6475

We propose to observe the open cluster NGC 6475 (age virgul220 Myr, Fe/H 0.14 +0.06) to investigate the activityrotationage relationship of lowmass stars inthe crucial age interval between the Pleiades and the Hyades. We will useXMMNewton observations of the proposed cluster to go a factor of 10 deeper thanROSAT (to detect new faint candidate members) and to obtain spectral informationon the brightest cluster members (to derive coronal temperatures andmetallicities). These observations will provide strong constraints on theuniversality (or lack of) of the activityrotationage relationship, and henceon dynamo models of stellar coronal activity. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]