Stellar rotation in h Per

We conducted a multi-site photometric monitoring of the young open cluster h Persei that has an age of ~13Myr. The observations were done in the I-band using 4 different telescopes and the variability study is sensitive to periods from less than 0.2 day to 20-days.

Rotation periods are derived for 586 candidate cluster members over the mass range 0.4<=M/M_{sun}_<=1.4. The rotation period distribution indicates a slightly higher fraction of fast rotators for the lower mass objects, although the lower and upper envelopes of the rotation period distribution, located respectively at ~0.2-0.3d and ~10d, are remarkably flat over the whole mass range. We combine this period distribution with previous results obtained in younger and older clusters to model the angular momentum evolution of low mass stars during the PMS.