EW of the helium 1083 nm line across orbital phases (top) in comparison to the surface density projected along the radial direction of the planetary wind, ∑_pw, along the orbit of model S1 (bottom). In the spectral light curve, we show two different density scalings, s, of the same simulation snapshot: one that matches the in-transit absorption (S2, blue) and one that fits the post-transit absorption (S2*, gray). The black circles indicate the angular sizes of the planet and the star. The local maximum at φ = −0.2 in the light curve can be explained by the large vertical extent of the gas, a result of instabilities induced by the stellar wind.