Si III line in Visit A_fuv, plotted as a function of wavelength in the expected star rest frame. The green line shows the theoretical profile for the intrinsic stellar line, which is convolved with COS LSF (yielding the red spectra) to be compared to the observations (black spectra). The dashed black line shows the expected rest wavelength of the stellar line, and the dashed red line its measured central wavelength. We note that COS LSFs are asymmetrical and off-centered, hence the observed stellar lines are slightly distorted compared to the intrinsic lines.