Astronomy and astrophysics vol:269 issue:1-2 pages:242-248
We report new radial velocity measurements of the F2 supergiant 89 Her, that confirm the binary nature of this star. A period search yields an orbital period of 288.4 +/- 0.7 days, in close agreement with earlier results. We also present intermediate resolution spectra in the wavelength range 3500-11000 angstrom, with numerous emission lines. We use the available spectroscopic and photometric data to construct a qualitative model for the circumstellar envelope of 89 Her, and suggest that it is highly non-spherical as a result of binary evolution. We discuss the evolutionary status of the 89 Her system.