2004PASP..116..558K

On the basis of a new classification-resolution spectrum, we find that HD 221866, a member of the newly discovered γ Doradus variable-star class, is an Am (metallic-line A-type) star. Observations with the Cambridge radial-velocity spectrometer reveal that the star is a double-lined spectroscopic binary with a period of 135 days and a mass ratio of 1.11±0.03. We have determined the basic physical parameters of both components through spectral analysis of the classification-resolution spectrum and a medium-resolution spectrum from the KPNO coudé-feed spectrograph in conjunction with fluxes from visible spectrophotometry and the TD-1 satellite. We confirm the results of Fekel et al. that the primary is the Am star, whereas the secondary appears to be a normal early F-type dwarf. We reanalyze the time-series photometric data for HD 221866 and confirm the existence of two periods found by Henry & Fekel.