Poster Presentation

Measuring Rotational Speed by High-Dispersion Spectra of Classical Be Stars with Infrared Excess

Pei-Min Shen, Wen-Ping Chen, Chien-De Lee, Chien-Cheng Lin

Classical Be stars are B-type stars with the characteristic emission spectra and infrared excess. These stars are distinct from the pre-main sequence Herbig Ae/Be stars and are known to be rapid rotators, some perhaps close to break-up. They are surrounded by gaseous disks, which are responsible for many of the observed properties, including plausibly the dust condensation in the ejected cooling envelopes. We present the echelle spectra taken by Tai National Telescope(TNT) of NARIT of three classical Be stars BD+56573 ,HD50138, HD 50820. in order to derive their rotational velocities, and discuss the hypothesis of how fast rotation may have played a role in the Be phenomena.