Cyclic variability of the circumstellar disk of the Be star<i>ζ</i>Tauri
Cyclic variability of the circumstellar disk of the Be star<i>ζ</i>Tauri
<i>Context. <i/>About 2/3 of the Be stars present the so-called variations, a phenomenon characterized by the quasi-cyclic variation in the ratio between the violet and red emission peaks of the emission lines. These variations are generally explained by global oscillations in the circumstellar disk forming a one-armed spiral density pattern …