Equatorial vs. projected rotation velocity. v_eq is derived from the stellar radius and rotation period, and v sin i originates from fitting the rotational line broadening. The blue dots display stars with an upper limit on v sin i, and red circles show stars with nominal values for v sin i. The dashed lines indicate 2 km s⁻¹ in v sin i and v_eq. The linear $1:\frac{4}{\pi }$ relation (solid black line) corresponds to the expected value of sin i for an isotropic distribution of the inclination angles (see Appendix B). The relations 1 : 1 and $1:\frac{1}{2}$ corresponding to i = 90° and $i=arcsin\frac{1}{2}=30$ ° are shown for comparison (solid gray lines).