BIS vs RV of ESPaDOnS 2016 (top), 2019 (middle), and SPIRou (bottom) observations. The colour code scales the HJD of observations. The red dotted line shows the best linear regression with slope "a" and intercept "b" indicated in legend. The uncertainty on the regression is shown as the grey-shaded area The green dotted line has a slope of −1 and an intercept equal to the mean radial velocity.