Maximum perturbation of the surface angular velocity at the equator for e=0.5 plotted as a function of time. The velocity is measured in the reference frame at rest in the rotating star. Positive values indicate motion in the direction of the orbital motion, negative values motion opposite to the orbital motion. Vertical lines indicate times of periastron. Left: All models with β₀ increasing from top to bottom. Models close to pseudosynchronism are not labeled for clarity in the figure. Right: Models with 0.60≤β₀≤1.00 are plotted in blue and cyan and those with 1.05≤β₀≤1.20 in red.