Secular evolution of a star–planet system with M_* = 1 M_⊙, a_ini = 0.035 AU, and m_p = 1 M_Jup. The initial stellar rotation period was set to 8 days (dark blue lines), 5 days (blue lines), and 1.4 days (light blue lines). Top panel: rotation rate of the envelope (solid lines) and of the radiative zone (dashed lines) of the star. Middlepanel: semi-major axis (solid lines), corotation radius of the star (dashed lines) and limit of excitation of the dynamical tide (dotted lines). Bottom panel: modified quality factor.