  The Kepler space telescope monitors over 156.000 stars with an unprecedented
photometric precision. We are interested in stellar rotational periods which we
find using Lomb-Scargle periodograms. This work focuses on the 306 exoplanet
candidate host stars released on June 15, 2010. We present statistics on how
many of them show periodic photometric variability, providing preliminary
periods and estimates of stellar activity. In the future, our work will focus
on spot evolution and differential rotation.
