Projected rotation velocity vsini as a functionof stellar mass. Stars with detected Hα emission are shown as filled circles, and stars with no Hα emission are shown as open circles. Colors indicate the level of Hα emission as shown in the legend. Slow rotators are plotted at our detection limit of v sin i = 2 km s⁻¹. The red dashed line indicates values of v_Eq for stars with rotation periods P = 10 d. Above this line, Hα is always expected in emission (see text).