Top panel: high-precision RV measurements for HATS-2 from CORALIE (dark filled circles), FEROS (open triangles) and CYCLOPS (filled triangles) shown as a function of orbital phase, together with our best-fit model. Zero phase corresponds to the time of mid-transit. The center-of-mass velocity has been subtracted. Second panel: velocity O−C residuals from the best fit. The error bars include a component from astrophysical/instrumental jitter allowed to differ for the three instruments (see Sect. 3.3). Third panel: bisector spans (BS), with the mean value subtracted. Note the different vertical scales of the panels.