Left panel: variation of the energy needed to bring a unit-mass planetary material up to the Roche lobe as a function of the mass of the planet and of the orbital distance. The green line corresponds to the case when the planet is in isolation, showing the energy needed to bring a unit mass to infinity. The red lines corresponds to cases where the planet is sufficiently near the star so that the energy would be lesser than the former case, which is needed for bringing a unit mass only up to the Roche lobe between the planet and the star. From top to bottom, red lines correspond to orbital distances equal to 0.1, 0.05, 0.04, 0.03, 0.02, and 0.01 au. Right panel: variation of the initial evaporation timescale of planets of different masses irradiated by different XUV fluxes. The green line corresponds to a flux equal to 10^4.5 erg s⁻¹. The lowest red curve corresponds to a flux equal to 10^5.5 erg s⁻¹. The lines in between correspond to intermediate values, from 10^4.6 to 10^5.4 in steps of 0.1 dex. The distance between the planet and the star has been assumed to be 0.1 au for the continuous lines and 0.01 au for the dashed lines.