The variable nature of the OB star HD13831
Preliminary data for the star HD13831, shows variability in the Hα and HeII4686 emission line
profiles, with a variability cycle of approximately 70 days. We intend to confirm the orbital solution
as well as the nature and variability of the star. We present high resolution optical spectroscopy,
with good orbital phase coverage, of the B0 IIIp type star HD13831. Radial velocity determinations
were made from the He I absorption lines, which along with measurements of the V/R ratio, found a
period of 70.76 days. The V/R variability exhibited both a periodic cycle of 70.76 days, and a disc
growth cycle typical of a Be/X-ray binary star. We therefore suggest that this star is in fact a Be/X-
ray binary star in quiescence, likely associated with the ROSAT source 1RXS J021639.3+564406.