Observed stellar CCFs of MASCARA-1 obtained by cross-correlating the full ESPRESSO spectrum with an A0 mask during the transit without correcting the systemic velocity. Both nights are shown together, ordered according to the orbital phase of the planet, which is indicated in different colours. The thick coloured lines show the CCFs binned by 0.01 in orbital phase, and the averaged out-of-transit CCF is shown as a dashed black line. The CCFs have been normalised for a better visualisation. The inset shows a zoomed-in view of the core of the CCFs, where the Doppler shadow of MASCARA-1b can be clearly observed.