Disks Surrounding Be stars: A Stellar Evolution Perspective

摘要

There is evidence that at least some stars undergoing the Be phenomenon are single, almost critically rotating stars surrounded by viscous Keplerian disks. By combining our new stellar evolutionary tracks for critically rotating B-type stars with different masses and metallicities, with the parametrized expressions by Krti?ka et al. (2011) describing the properties of a stationary viscous Keplerian disk surrounding a star rotating at its breakup limit, we are able to explore for the first time how the properties of such a disk changes along the main sequence evolution of the star. The results we obtain can be relevant in the understanding of the formation and existence of Keplerian viscous decretion disks around rapidly rotating single Be stars.