Rotational broadening and line distortion. Upper panels: rotational broadening of the Fe i line at 617.3 nm for the G2V (left) and M0V (right) simulations. The narrow right subplots of each plot show the bisectors of the lines (same colour code and ordinate labels as other subplot). Lower panels: same as upper panels, but for the Ti i line at 2223 nm. In all cases, we used solar differential rotation together with five different rotation rates.