Binary Nature and Long-Term Variations of (gamma) Cassiopeiae

We present the results of high-resolution spectroscopic observations of the bright Be star &#x03B3 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&#x03B1 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 nondegenerate 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 timescale 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&#x03B1 line profile shape and those of nonhydrogen lines. This suggests the presence of an additional component in the H&#x03B1 line profile that may originate in the outer regions of the primary’s disk. This might manifest the beginning of a new phase in the evolution of &#x03B3 Cas, which could lead to a new normal B star phase