HD-37017 = V-1046 ORI - A DOUBLE-LINED SPECTROSCOPIC BINARY WITH A B2E HE-STRONG MAGNETIC PRIMARY

We report on a detailed spectroscopic and photometric study of V1046 O rionis undertaken to resolve uncertainties about the period(s) and cau ses of the spectroscopic and photometric variations of this helium-str ong star. We have detected the lines of the secondary star in an exten sive series of photographic and electronic spectra. This eliminates an y doubt about the duplicity of this star. The orbital elements we deri ve from our measures of these spectra confirm the unusually large orbi tal eccentricity, e = 0.433, for the short, P = 18.(d)65612, orbital p eriod. The line profiles, VIR ratio of the double H alpha emission, re siduals of the primary radial velocities from the orbital velocity cur ve, brightness and colour of the object, magnetic field, and radio emi ssion of this system all vary with a period of 0.(d)9011836. We tentat ively follow earlier investigators in interpreting this as the rotatio nal period of the primary and summarize the evidence of the phase shif ts among the different phenomena, using the accurate value of the O.(d )9 period, to put tight constraints on any future model of these chang es. We postpone our own attempt at a quantitative modelling of the var iations with the 0.(d)9 period for a separate study.