Large, Oscillating Be Star Circumstellar Disks

We present numerical model calculations (3D, NLTE radiative line transfer) for the cyclic, long-term variations of Be-star emission lines. These variations are believed be formed in quasi-Keplerian disks with single-armed global disk oscillations (Okazaki 1991, PASJ 43, 75). In our recent study (Hummel & Hanuschik 1997, A&A 320, 852), we showed that global disk oscillations in disks with R d = 5 R * can indeed account for both the observed line-profile asymmetries and their cyclic evolution.