Variability of emission lines in the optical spectra of the Herbig Be binary system HD 200775

In our previous papers we have improved the value of the orbital period of the binary Herbig Be star HD 200775 and showed that the [O I] and Si II 6347 and 6371 Å emission lines displayed variations which correlate with the orbital period. In this paper we provide evidences that other broad emission lines of metals in the spectra of HD 200775 also exhibit variability, which is probably related to the orbital cycle of the binary. Analysis was performed based on the high-resolution spectral data collected over a time span of 6 years at the Kourovka Astronomical Observatory of the Ural Federal University (Russia) and the Three College Observatory of the University of North Carolina at Greensboro (USA) as well as archival spectral data compiled since 1994. We report new data points in the radial velocity curve of the He I 5876 Å line near the extremal values of the radial velocity. © 2019 National Astronomical Observatories, CAS and IOP Publishing Ltd.