Hα mean line width at 10% of peak intensity (from Paper I) vs. the projected rotational velocities (circles). Lower limits for  ⟨ W₁₀(Hα) ⟩  are marked with vertical bars. Open circles indicate HBe stars – 51 Oph the object with the highest value of vsini –. Filled circles represent the stars in our sample with later spectral types. The theoretical lower limit estimates for each object are derived from Eq. (14), and are plotted as open triangles (see text).