Left panel: detrended one-day binned mean radial velocity RV_m of α Cen Bmeasured on all the spectral lines. Uncertainties are displayed, but are too small to be visible. Middle panel: detrended one-day binned individual radial velocity RV_i of the Fe I line at 4112.30 Å. Right panel: weighted linear regression between RV_i and RV_m (red line). The coefficient as well asthe correlation slope are indicated in the legend. The peak-to-peak variation due to activity is ~10 m s⁻¹ in the RV_m and ~30 m s⁻¹ in the RV_i of the Fe I line at 4112.32 Å.