Upper two panels: phase-time diagrams computed from Doppler images by averaging them over latitude ranges. The temperature range for both is 4527–5148 K. We include the averages from the 45–90° range in the top panel and the 0–45° range in the middle panel. We overplot with the phases of the photometric minima derived by Olspert et al. (2015), the green squares showing the primary minima and the blue triangles the secondary minima. Bottom panel: latitude-time diagrams computed by averaging the Doppler images over the whole longitude range. The temperature range is 4464–5230 K.