Water vapor lines in the region of D1 and D2 sodium lines. The TAPAS transmission spectrum is in blue, at the top. All lines of the model are seen in the star spectrum. The corrected spectrum has three versions with 3 different resolutions. Regardless of the spectral resolution chosen to compute the TAPAS spectrum, there are residual absorption features that indicate that the quantity of H₂O in the model is less than in reality.