Fraction of binaries among the slow rotators (blue) against (G − G_RP)₀. The higher-mass stars are nearly exclusively slow rotators, hence the relative binary fraction (orange) is roughly unity. For stars beyond the threshold value (dashed line, see text), the binaries are equally distributed between fast and slow rotators, pointing to a small effect of binarity on stellar rotation. The overall binarity fraction is shown in black. In the background, we included the CPD for reference. Here, black symbols mark the slow rotators, while all other stars (fast rotators for this discussion) are in grey.