Lyman-α line of GJ 3470, plotted in the stellar rest frame. The blue and orange profiles show the COS spectra corrected for airglow contamination and averaged, respectively, over the out-of-transit and in-transit HST orbits in Visits D and E. Light profiles are the spectra at the original COS resolution, while strong profiles are binned with a 10 km s⁻¹ resolution. The black profile is the best-fit model to the observed STIS Lyman-α line from Bourrier et al. (2018a).