Evolutionary history of planet HD 63433 b. (a) Mass-loss rate vs. time for different values of the planetary mass at the present age. (b) Fraction of planetary mass lost vs. time. Panels c and d show the evolution of the planetary mass and radius, respectively. Dashed lines indicate backward time evolution from the current age, solid lines forward time evolution. Note that all the simulations were constructed with the boundary condition that the planet completely lost the atmosphere at the present age of 414 Myr.