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K.S. Bjorkman, A.S. Miroshnichenko (U. Toledo), V.D. Krugov (Ukranian Acad. of Sci.)
High-resolution spectroscopic data (\lambda\lambda 5285-6595 Å) for three bright classical Be stars with unusual H\alpha profiles (\gamma Cas, \zeta Tau, and \pi Aqr) have been obtained during the time period 1993-2000 at the Ritter Observatory of the University of Toledo. The data for \gamma Cas are supplemented by medium-resolution spectroscopy taken at the Terskol station of the Main Astronomical Observatory of the Ukranian Academy of Sciences. The stars show the presence of an additional variable (central) emission peak in the H\alpha line, which has a double-peaked profile in most stars of this type. Long-term radial velocity (RV) variations of H I, He I, Si II, and Fe II lines are detected in \gamma Cas and \zeta Tau. The RV of the central peak of H\alpha in \zeta Tau seem to follow the binary orbital motion (period 132.9 days) on top of the long-term variations (period 1420 days). In \gamma Cas this peak shows a constant trend towards negative velocities since 1993, which is opposite to the behavior of other emission lines. Short-term RV variations of the H\alpha emission peak with a period 84 days are found in \pi Aqr during its weak-disk phase (since 1996).
This work has been supported in part by NASA grant NAG5-8054 to the Univ. of Toledo, and by a Cottrell Scholars Award to KSB from the Research Corporation. Support for Ritter Observatory has been provided in part by NSF grant AST-9024802, and in part by a grant from the Fund for Astrophysical Research.
The author(s) of this abstract have provided an email address for comments about the abstract: karen@astro.utoledo.edu