Panel a): HARPS-N radial velocities associated with the Gaussian fit of the cross-correlated line profile (RV_cc−g using F5I template) plotted as a function of the pulsation phase of the star after correction of the γ-velocity (i.e., V_γ = −16.95km s^-1 ). The cycle of observations are shown in different colors. The data are reproduced from one cycle to the other. The precision on the measurements is between 0.5 and 1.5 m s^-1 (error bars are lower than symbols). Panel b) residuals between RV_cc−c (F5I) and RV_cc−g (F5I) after correction of their respective γ-velocities.