Properties of the telluric correction best-fit. First panel: barycentric correction as a function of time for Tau Ceti observations. Second panel: IWV as a function of time. In blue is the airmass scaled IWVlos as measured by the radiometer and in orange is the best-fit IWV value. Third-panel: pressure as a function of time. In blue is the measured ground pressure (it is the upper limit to the fitted pressure) and in orange is the best-fit pressure value. Last panel: best chi-square values of the fit of the automatic telluric correction.