  CI Tau is a young (~2 Myr) classical T Tauri star located in the Taurus star
forming region. Radial velocity observations indicate it hosts a Jupiter-sized
planet with an orbital period of approximately 9 days. In this work, we analyze
time series of CI Tau's photometric variability as seen by K2. The lightcurve
reveals the stellar rotation period to be ~6.6 d. Although there is no evidence
that CI Tau b transits the host star, a ~9 d signature is also present in the
lightcurve. We believe this is most likely caused by planet-disk interactions
which perturb the accretion flow onto the star, resulting in a periodic
modulation of the brightness with the ~9 d period of the planet's orbit.
