Comparison of in-transit (orbit 2: dotted) to out-of-transit (orbit 4: solid) line profiles. We binned spectra by 4 (~7.5 km s^-1), approximately corresponding to the nominal spectral accuracy of the dispersion of the COS/G130M grating. A redshift of ~2.6 km s^-1 of the star was corrected for (Bouchy et al. 2005). It is important to stress that the COS wavelength calibration does not allow one to know the relative position of the lines with an accuracy better than ~7.5 km s^-1 (Oliveira et al. 2010). For the available low S/N COS dataset, this inaccuracy makes the interpretation of the transit absorption line profile very uncertain, particularly the veracity of any blueshift or redshift that may appear between in-transit and out-of-transit line profiles. a) OI 130.6 nm line. b) C II 133.5 nm line. c) Si IV 139.3 nm line.