Gaia HRD (BP − RP, M_G) of low mass stars (grey) with those identified as showing significant variability of the rotational amplitude over time shown as circles whose size indicates their Gaia RUWE value (see text for details) on the left. The low mass star sample (orange dots) is on the right-hand panel, with the 29 stars which were identified as having a rotational amplitude which varies significantly over time shown as a red × symbol.