Analysis of the BIS and contrast of the ESPRESSO CCF. a, b: BIS and contrast time-series with the best-model fit. The data is split into two panels because of a large period with no observations between the two campaigns. The shaded area shows the variance of the GP model, c: GLS periodogram of the CCF BIS and contrast data. The red vertical dashed line shows the most significant period, d: Relationship between the CCF RV and CCF BIS and contrast data. The best fit is shown when the slope is ≥3σ different from zero, e, f: Residuals of the CCF BIS and contrast after subtracting the best model fit. g: GLS periodogram of the residuals, h: Comparison of the CCF RV and gradient of the CCF BIS and contrast model.