Surface temperature as a function of the effective flux received on a planet (x-axis) and the surface pressure of its steam H₂O atmosphere (y-axis), for three different surface gravities (0.3, 1 and 3× the gravity on Earth). The surface temperature was estimated using Eq. (1). The small black dots indicate the parameter space for which atmospheric numerical simulations have been carried out, and on which the fit of the surface temperature is based.