Top: estimates of the maximum possible duration of the stationary state τ_sta as a function of the orbital mean motion in units of the critical mean motion n_c0. The computations were done for a G-type star (black) or F-type star (blue) and planetary masses of 0.1 (dashed), 1 (solid), and 10 (dotted) Jupiter masses. We used Q′ = 10⁷ for both G- and F-type stars, while the magnetic braking coefficient α_mb is reduced by a factor of ten for F-type stars (see text). Bottom: the same, but the orbital mean motion is in units of n_3d = 2π/ (3 days), hence independent of planetary and stellar mass.