Recent Progress in Finding Binary Systems with the B[e] Phenomenon
Anatoly S. Miroshnichenko,
Sergei V. Zharikov,
Nadine Manset,
Serik A. Khokhlov,
Atilkhan S. Nodyarov,
Valentina G. Klochkova,
Stephen Danford,
Aizhan K. Kuratova,
Ronald Mennickent,
S. Drew Chojnowski,
Ashish Raj,
Devendra Bisht
Affiliations
Anatoly S. Miroshnichenko
Department of Physics and Astronomy, University of North Carolina at Greensboro, Greensboro, NC 27402, USA
Sergei V. Zharikov
Faculty of Physics and Technology, Al-Farabi Kazakh National University, Al-Farabi Ave., 71, Almaty 050040, Kazakhstan
Nadine Manset
Canada-France-Hawaii Telescope Corporation, 65-1238 Mamalahoa Hwy, Kamuela, HI 96743, USA
Serik A. Khokhlov
Fesenkov Astrophysical Institute, Observatory, 23, Almaty 050020, Kazakhstan
Atilkhan S. Nodyarov
Faculty of Physics and Technology, Al-Farabi Kazakh National University, Al-Farabi Ave., 71, Almaty 050040, Kazakhstan
Valentina G. Klochkova
Special Astrophysical Observatory of the Russian Academy of Sciences, Nizhnyj Arkhyz, Zelenchukskiy Region, 369167 Karachai-Cherkessian Republic, Russia
Stephen Danford
Department of Physics and Astronomy, University of North Carolina at Greensboro, Greensboro, NC 27402, USA
Aizhan K. Kuratova
Faculty of Physics and Technology, Al-Farabi Kazakh National University, Al-Farabi Ave., 71, Almaty 050040, Kazakhstan
Ronald Mennickent
Departamento de Astronomía, Universidad de Concepción, Concepción 4030000, Chile
S. Drew Chojnowski
Department of Physics, Montana State University, Bozeman, MT 59717, USA
Ashish Raj
Indian Centre for Space Physics, 466 Barakhola, Netai Nagar 700099, India
Devendra Bisht
Indian Centre for Space Physics, 466 Barakhola, Netai Nagar 700099, India
This paper describes recent studies of the FS CMa-type objects, a group of stars showing the B[e] phenomenon defined in 2007. The objects exhibit strong emission-line spectra with both permitted and forbidden lines suggesting the presence of a B-type star as well as strong IR excesses due to radiation of circumstellar dust. These properties are hard to explain in the framework of the evolution of single stars with luminosities between ~300 and ~30,000 L⊙ typical of most B-type stars. We explore the hypothesis that the gaseous-and-dusty envelopes of FS CMa objects are due to either earlier or ongoing mass transfer between the binary system components. It is hard to detect the secondary components in these systems because of veiling and distortions by the circumstellar matter because of the relative faintness of the companions. Nevertheless, we detected regular radial velocity variations of the spectral lines in MWC 728, 3 Pup, and AS 386 and we found absorption lines typical of cool stars in the spectra of MWC 645, AS 174, and several other objects. The diversity of the secondary components in FS CMa objects is discussed in the context of non-conservative binary evolution.
