Evolution of the tertiary star in ξ Tau (top panel) and HD 97131 (bottom panel) as predicted by various stellar evolution codes: evtwin (blue drawn line), mesa with and without convective overshoot (red dotted and green dashed lines, respectively), and seba and sse (magenta dashed and cyan dash–dotted lines, respectively). The horizontal dotted curve gives the size of the Roche lobe of the outer star in ξ Tau and HD 97131 of 0.42 and 0.26 au, respectively.