Top: astrometric orbit of HD 16702 projected on the sky. North is up and east is left. The solid red line shows the model orbit, which is orientated counter-clockwise, and open circles mark the individual Hipparcos measurements used for the astrometric fit. Blue filled circles show normal points for each satellite orbit number and are used for display only. Bottom: O − C residuals for the normal points of the orbital solution (filled blue circles) and the five-parameter model without companion (crosses).