Top panel: Tomography plot of the individual absorption spectra near the Hα line for a simulated hot Jupiter, including the effect of a stellar spot. Bottom panel: Mean in-transit planetary absorption spectra around the Hα line. The horizontal black lines represent the four transit contacts, while the dashed white line traces the center of the line. Both plots are shown in the planet’s rest frame. For this case, the spots parameters are: f_sp = 1%, θ_lat = 25°, θ_lon = 20°.