SIMBAD references

A detailed analysis of a large collection of electronic spectra from three observatories, together with radial velocities published earlier, were used to derive a new ephemeris and improved orbital elements for the ε Per binary. Observations covering a time interval of about 37000-days (101.3-years) can be reconciled with a constant orbital period of 14.06916±0.00004^d. The high orbital eccentricity of 0.555±0.009 was also confirmed. New spectral observations confirm that there is a periodic variation of the systemic velocity. Together with new evidence from astrometric observations (also analyzed here), they confirm the existence of a third body in the system with an orbital period of about 9600-days (26.3-years), rather than 4156-days, as reported earlier. Application of the disentangling technique to the Hα spectra with good S/N ratios did not allow detection of spectral lines of either the secondary or tertiary components. For plausible inclinations between 30° and 90°, the observed mass function implies a mass of the secondary M₂=0.85-1.77M_☉, if a primary mass is adopted of 13.5±2.0M_☉. Attempts to detect the third body via interferometric observations should continue in spite of this first negative result.