One of the best-fit solutions for the ξ Tau system with our N-body model and using all available observational data. In this case, the resulting total χ² is 2578, while the number of degrees of freedom ν = 908. Top: radial velocities v_zbAa, v_zbAb, v_zbB, v_zbC of the individual components; model values are denoted by lines (component Aa is black, not clearly visible, Ab grey, B blue, and C orange), observations by black error bars and residuals by thick red lines. Middle: O−C values for both primary and secondary minima timings; model timings are denoted by black points (very densely packed), observations by grey crosses, and O−C with its uncertainty by red error bars. Bottom left: astrometric positions of component B based on NPOI interferometric observations; model orbit x_pB, y_pB with respect to photocentre Aa+Ab (i.e. not w.r.t. B, as usually) is again denoted by a blue line, observations by black error bars and residuals by thick red lines. The orbit is not a single ellipse, but rather a complex trajectory that quickly precesses and is moreover affected by (slight) photocentre motions. Bottom right: similarly, astrometric positions of the distant component C x_pC, y_pC with respect to the Aa+Ab+B photocentre is denoted by an orange line. Component B is relatively luminous, which makes the orbit in these photocentric coordinates slightly jagged.