Relative change in the bulk density of close-in planets, Δρ = 1 − ρ/ρ_s, as a function of the distance to the star r₀. The red curve is relative to gaseous planets (h_f = 1.5), while the blue one is relative to rocky planets (h_f = 2.0). Both curves are obtained using expression (27) with i = 80°. The dots represent the planets listed in Table 1. For r₀> 1.5 r_R, the change is negligible when compared to the present observational errors in the density determination.