Pre-processing steps applied to obtain cross-correlation functions in the rest-frame of the planet, as described in Sect. 2.3.3. Panel A: an example spectral order of night one as extracted by the HARPS DRS, plotted as a time-series. Panel B: after normalisation by the time-average flux and colour correction. Panel C: cross-correlation template of Fe I after continuum-subtraction, with which the spectra are cross-correlated. Panel D: average flux in the spectral order, that is divided out of the spectra in panel A to obtain the spectra in panel B. Panel E: cross-correlation function of Fe I of the entire time series. Panel F: after removal of the time-average of the out-of-transit cross-correlation functions. Panel G: after removal of the Doppler shadow and application of the high-pass filter. Panel H: after shifting the cross-correlations to the rest-frame of the planet. Panel I: after weighing the cross-correlation functions by the average flux of the time-series (panel D) and selecting only in-transit observations. Panel J: one dimensional cross-correlation function in the rest-frame of the planet, after averaging the cross-correlation functions (panel I) in time.