¹ Ritter Observatory, Dept. of Physics & Astronomy, University of Toledo, Toledo, OH 43606-3390
² Central Astronomical Observatory of the Russian Academy of Sciences at Pulkovo, 196140, Saint-Petersburg, Russia
³ Main Astronomical Observatory of the Ukranian Academy of Sciences, 252650, Kiev, Golosiiv, Ukraine

We present the results of high-resolution spectroscopic observations of the bright Be star  Cas obtained at the Ritter Observatory of the University of Toledo in 1993-2002. Two components in the emission-line profile variations, a long-term and a periodic one, are found. The periodic component is represented by changes of the mean radial velocity of the H line with a period of 205 days, which is most likely related to the orbital motion in a binary system. This finding confirms a recently reported result of Harmanec et al., although our data suggest a circular orbit rather than the eccentric one they derived. The zero eccentricity favors a non-degenerate nature of the secondary and supports a hypothesis that the companion is not connected with the X-ray generation. The long-term variations are represented by changes in the peak intensities and radial velocities of the spectral lines on a time scale of a few years and include a continuous decrease of the line intensities in 1993-2001. We also found a different behavior of the H line profile shape and those of non-hydrogen lines. This suggests the presence of an additional component in the H line profile which may originate in the outer regions of the primary's disk. This might manifest the beginning of a new phase in the evolution of  Cas which could lead to a new normal B-star phase.

2002 PASP, 114, 1226
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