Evolution of the stellar radius (top left, plain line), the radius of the radiative zone (top left, dotted line), the density at the interface core-envelope (top right), the gradient of the square of the Brunt–Väisälä frequency at the interface (bottom left) and the forcing term (bottom right) as a function of the age of the system for stellar masses (M_⋆) between 0.4 and 1.4 M_⊙, with P_orb = 1 d, a typical value for a hot Jupiter. The colored squares correspond to the ZAMS in each model, and the colored circles represent the TAMS.