Upper panel. PDC-MAP LC light curve of Kepler-77, with the location of known instrumental systematic features marked by blue dashed lines. Grey and white bands denote the zero-normalised Q₃–Q₁₃ data. Middle panel. Cleaned and zero-normalised light curve, following subtraction of the best-fitting transit model. Rotational period intervals are shown with red dashed lines. The arrows mark groups (per colour) of repeated features. Lower panel. Autocorrelation function (ACF) of the cleaned and zero-normalised light curve. The red dashed line marks the peak corresponding to the 36-day rotational period of Kepler-77.