2001PASP..113..821F

HD 223960, an A0 Ia-type supergiant in the Cas OB5 association, is unusual among Galactic supergiants of its class in having an Hα profile with double-peaked emission entirely above the continuum. We analyzed 12 high-resolution échelle spectra obtained in 1993-1995 and in 1999 with the 1 m telescope of Ritter Observatory. The radial velocities of photospheric Si, C, He, Ne, and S lines were found to be constant to within ±2 km.s^–1, but the data suggest variability in the equivalent widths of Si II λλ6347, 6371 and several other photospheric lines. The radial velocities and equivalent widths and, especially, the ratio V/R of the Hα components vary. The present data do not indicate a binary explanation for the double-peaked emission feature. Alternative explanations are considered, but none is completely satisfactory. The available evidence is consistent with the star having a weak, fast wind.