Details

Autor(en) / Beteiligte

• Fischer, William J.
• Morrison, Nancy D.

Titel

Spectrum Variability of the A‐Type Supergiant Star HD 223960

Ist Teil von

• Publications of the Astronomical Society of the Pacific, 2001-07, Vol.113 (785), p.821-828

Ort / Verlag

The University of Chicago Press

Erscheinungsjahr

2001

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• 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 Siiiλλ6347, 6371 and several other photospheric lines. The radial velocities and equivalent widths and, especially, the ratio \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $V/ R$ \end{document} 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.