Light curves retrieved with limb-darkening (Juliet) and without (batman) and residuals. For each case (2D day–night and WASP-121b): Left: light curves generated by Pytmosph3R (dashed line) compared to Juliet (solid line, with retrieved limb darkening, T₀ and R_P). Right: residuals of Juliet (orange) to Pytmosph3R, with batman (no limb darkening, T₀ = 0 and R_P taken at mid-transit from Pytmosph3R) given as a reference.