Transit search with various de-trended photometric data sets. Top panels: four high-cadence nights from the transit search. The transit model (black curve) shows the expected signal for planet b and for maximum transit depth. The left and right models (grey) indicate the predicted 1σ uncertainty for the transit window (0.15 d, 3.6 h). Bottom panel: all photometric data phase-folded with P_b and t_ic,b.