Evolution of the equatorial velocity at the surface of a 2 M_⊙. The dashed line corresponds to the evolution obtained from a model with an initial surface angular velocity equal to 10% of the critical angular velocity without tidal interaction. The continuous line corresponds to the same model but accounting for the transfer of angular momentum from the planetary orbit to the star (15 M_J planet beginning to orbit at 1 au on the ZAMS). The line stops at engulfment. The two horizontal dotted lines indicate the maximum velocities that can be produced in some extreme situations from single stars at the position in the HR diagram where engulfment occurs. The lowest limit corresponds to models computed with the same physics of rotation as here but starting from a much higher initial rotation equal to about 95% the critical rotation on the ZAMS. The upper limit would correspond to a model starting with the same very high initial velocity, assuming solid-body rotation during its whole evolution.