Maximum perturbation of the surface angular velocity at the equator plotted as a function of time for e=0.1 (left) and e=0.3 (right). The velocity is measured in the rest reference frame of the rotating star. Positive values indicate motion in the direction of the orbital motion, negative values to motion opposite to the orbital motion. Vertical lines indicate times of periastron. Each curve is labeled with its value of β₀. The smallest tidal perturbations for e=0.1 occur for β₀=0.88. For e=0.3, the β₀=0.80, 0.88, 1.00 and 1.05 curves show low amplitude oscillations and are very similar. The smallest perturbations are observed for β₀=0.95. Observational perspective: Surface layer is rotating faster than the inner core for β₀< 1 and rotating slower in β₀> 1 models. Also, these stars are likely to display variations in the shape of the photospheric line profiles as discussed in Moreno et al. (2005) and Harrington et al. (2009), Harrington et al. (2016). TEOs are evident mostly for β₀∼1 models.