Research Note

A potential ϕ Per-type (Be+sdO) binary: FY CMa^*

¹ Landessternwarte Königstuhl, 69117 Heidelberg, Germany e-mail: T.Rivinius@lsw.uni-heidelberg.de
² Astronomical Institute, Academy of Sciences, 251 65 Ondřejov, Czech Republic
³ European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching bei München, Germany

Received: 26 April 2004
Accepted: 12 August 2004

Abstract

The spectrum of the Be star FY CMa is shown to vary periodically with  d. The types of variation, exhibiting transient strong shell phases and a radial-velocity variable  emission component, suggest the star to be of the same type as ϕ Per, i.e. having an evolved hot companion ionizing the outer parts of the primary's circumstellar disc where it faces the hot companion. After ϕ Per and the candidates 59 Cyg and HR 2142, this is only the fourth promising candidate, although such systems should be relatively abundant. The similarities found between ϕ Per, 59 Cyg, and FY CMa include a radial velocity-variable  emission feature and a phase-locked V/R cycle. An ephemeris is given that allows a test of the proposed recurrent nature of a strong shell feature observed only in a single spectrum at present.