Transiting extrasolar planet WASP-33b

These frequencies correspond to the delta Scuti-type pulsation of the host star. None of these pulsation frequencies or their low-order linear combinations are in close resonance with the orbital frequency. We show that these pulsation components explain some but not all of the observed transit anomalies.

The grand-averaged transit light curve shows that there is a ~1.5mmag brightening shortly after the planet passes the mid-transit phase. Although the duration and amplitude of this brightening varies, it is visible even through the direct inspections of the individual transit events (some 40-60% of the followup light curves show this phenomenon). We suggest that the most likely explanation of this feature is the presence of a well-populated spot belt which is highly inclined to the orbital plane.

This geometry is consistent with the inference from the spectroscopic anomalies. Finally, we constrain the planetary mass to M_p_=3.27+/-0.73M_J_ by using our RV data collected by the TRES spectrograph.