Orbital configuration, spot position, and corresponding absorption spectra for the sodium D₁ line. Left panel: The planetary track is represented by a dashed line, with each open circle corresponding to an absorption spectrum of the same color, highlighting the local distortion. The colormap, ranging from blue to red, represents local velocities. Right panel: Evolution of the absorption spectrum as a function of the orbital phase. The spot-crossing effect induces a slight asymmetry that is visible in the local profiles in the stellar rest frame.