Astronomical Institute, Academy of Sciences of the Czech
2 Department of Physics and Astronomy, University of Victoria, Victoria BC V8W 3P6, Canada
3 Department of Theoretical Physics and Astrophysics, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
4 Astronomical Institute of the Charles University, Faculty of Mathemathics and Physics, V Holešovičkách 2, 180 00 Praha 8, Czech Republic
5 University of Wrocław, Astronomical Institute, Kopernika 11, 51-622 Wrocław, Poland
Received: 17 April 2014
Accepted: 29 May 2014
The spectrum of the Be star HD 161306 is shown to vary periodically with a period of ~100 days. The radial velocity of the He i 6678 Å emission peak varying in antiphase to the radial velocity of the Hα emission wings component suggests that the star is a binary similar to φ Per, 59 Cyg, or FY CMa, i.e. a radiatively interacting Be binary – a rare case among Be stars. This type of object is also called a φ Per-type binary or Be + sdO binaries. The range of radial-velocity variations of the strong emission peak in the helium line observed in HD 161306 is about 180 km s-1, similar to what is observed for these systems. We therefore conclude that HD 161306 may represent another case of a Be star with a hot subdwarf companion.
Key words: binaries: spectroscopic / stars: emission-line, Be / stars: individual: HD 161306
Based on observations obtained with the Perek 2-m Telescope at Ondřejov Observatory, Czech Republic, and with the 1.22-m Telescope of the Dominion Astrophysical Observatory, Canada. This work made use of the BeSS database, operated at LESIA, Observatoire de Meudon, France.
The spectra taken in Ondřejov (Hα and helium regions) are only available in electronic form (FITS format) at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (188.8.131.52) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/567/A57
© ESO, 2014