Normalized stellar spectrum of the F-type star at high resolution (black) and as seen by JWST/NIRSPEC (red bins) in prism mode (30 ≤ ℛ ≤ 65). Dashed blue bins represent the differential transmission spectrum at T = –0.25 h (see Fig. 2) arbitrarily scaled. The differential transmission spectrum was shifted by 1 to be visible together with the flux spectrum. The left panel shows a zoomed-in image of a deep and broad stellar line.