  We present a large sample of stellar rotation periods for Kepler Objects of
Interest (KOIs), based on three years of public Kepler data. These were
measured by detecting periodic photometric modulation caused by star spots,
using an algorithm based on the autocorrelation function (ACF) of the light
curve, developed recently by McQuillan, Aigrain & Mazeh (2013). Of the 1919
main-sequence exoplanet hosts analyzed, robust rotation periods were detected
for 737. Comparing the detected stellar periods to the orbital periods of the
innermost planet in each system reveals a notable lack of close-in planets
around rapid rotators. It appears that only slowly spinning stars, with
rotation periods longer than 5-10 days, host planets on orbits shorter than 3
days, although the mechanism(s) that lead(s) to this is not clear.
