Upper panel: Sandiford and FIES radial velocities measurements of Kepler-77 and Keplerian fit to the data. The systemic velocities for each instrument, as derived from the global modelling of the data (Sect. 5 and Table 3), have been subtracted from the RV measurements. Lower panel: bisector spans of the Sandiford and FIES cross-correlation functions versus RV measurements, after subtracting the systemic velocities. The error bars in the CCF bisector spans are taken to be twice the uncertainties in the RV data.