Total angular momentum of the CoRoT-11 system in units of the critical angular momentum as defined in Eq. (4.1) of Hut (1980) versus the orbital mean motion in units of the present mean motion n_obs. The stellar magnetic braking law has P_sat = 6.0 days. The black solid line indicates the total angular momentum values corresponding to tidal equilibrium. The black dotted line represents the stability limit for the equilibrium as given by Eq. (4.2) of Hut (1980). The solid blue lines show the backward evolution of the system for different values of the tidal quality factor . From left to right, the values of are: 5 × 10⁷, 3 × 10⁷, 2 × 10⁷, 10⁷, 3.8 × 10⁶, and 10⁶, respectively. The initial points of the evolution are marked by the filled blue dots.