Visualisation of the barycentric orbits. Top panels: the sky-projected orbits of HD 140667 (left), HD 158222 (centre), HD 217924 (right) are oriented clockwise, counter-clockwise, and counter-clockwise, respectively. North is up and east is left. The solid red line shows the orbital solution and open circles mark the individual Hipparcos measurements. Bottom panels: the corresponding O–C residuals for the normal points of the orbital solution (filled blue circles) and of the standard 5-parameter model without companion (black crosses).