Top: a phase plot of all file 2 to file 5 RVs (i.e. data from the literature). Bottom: a phase plot of all our new file 6 to file 9 RVs. SPEFO Hα and Hδ RVs were used for the new spg. 6 to 9 spectra. Small dots denote the O–C residuals from the orbital solution. All RVs in the two lower panels were corrected for the difference in γ velocities, adopting γ of the most numerous file 9 as the reference. In all plots, the orbital period of 2541 569 and the reference epoch of the periastron passage RJD = 43 838.65 from the first solution of Table 3 were used. The rms errors of individual RVs are shown whenever available.