Upper left panel: sky map of the Hartman et al. (2010) sample (red filled dots) with the Gaia rotational modulation variable sample (blue open dots) overlapped. The HEALPix in which we have stars from both samples are outlined, and the colour code indicates the starnumber ratio in each HEALPix. Upper right and bottom panels: Comparison of the P, G, and (G_BP − G_RP) distributions in Gaia and the Hartman et al. (2010) sample in the overlapping HEALPix. P is given in day units.