Centroid velocity (left y-axis) and Kepler photometry in mask 45 (right y-axis) during the only epoch where the space and ground-based data overlap in time. The colour coding is as follows: Hβ: black; Hγ: light blue; He i 4713 Å: dark blue; He i 4922 Å: cyan; He i 5015 Å: pink; He i 5875 Å: grey; He ii 4541 Å: green; He ii 5410 Å: yellow; C iv 5812 Å: orange; Si iii 4567 Å: purple. To guide the eye, the observed Kepler light curve is shown as dotted line while its mirrored version with respect to the average Kepler magnitude is shown as the full line.