Minimum eccentricity and circularization timescale as a function of tidal dissipation factor . Top panel: eccentricity required to reach a dissipation rate H = 10²⁹   erg   s^-1 in the planet. Bottom panel: time to evolve from the minimum eccentricity to the observed e ~ 0.02 for two values of the stellar tidal factor, ∞ (dashed) and 10⁶ (plain). The horizontal lines show the times required for CoRoT-2b to contract from 2 to 1.5 R_J, with the atmospheric boundary conditions as in Fig. 11.