Top: extracted light curve for K2-19, showing significant stellar variability. Middle: flattened and detrended lightcurve, showing transits of the inner planet (b, red), outer planet (c, green) and simultaneous transits of both planets (magenta). Some outlier points are not shown for clarity. Bottom left: the phase folded transits of planet b, excluding simultaneous transits and showing the best fit model. Some points (shown lighter than the others) displayed clear evidence of spot crossings by the planet and were excluded from the fit. Bottom right: same for planet c. Note the change in y-axis scale.