The Be star omicron Cassiopeiae

Abstract

AbstractThe analysis of radial velocities (RVs) of the Be star ο Cas from 27 high S/N spectra allowed us to revive the binary nature of this star, first suggested by Abt & Levy (1978, “AL”), but later refuted by several authors. The period search in our RV data based on measurements of Hα emission and He I λ6678 Å absorption profiles detected a dominant peak close to the 1033-d period found by AL. The resulting curves are very smooth. The rms error of the solution for the emission RVs is nearly 5 times lower than the scatter of the solution by AL. If the RV variations are due to orbital motion, then ο Cas turns out to be a challenging system with an unseen secondary component with mass comparable to, or even more massive than the primary.