Gaussian process model fit to the RV data of TZ Ari from HIRES (blue), HARPS (green), and CARMENES VIS (red). The orbital parameters are listed in the right column of Table 4. The rotational modulation of the RV is far too fast to be seen at any reasonable screen or print resolution; the full range of this variation is therefore seen as a grey band. We provide a zoom into a short section in Fig. 12.