Hydrodynamics of Decretion Disks of Rapidly Rotating Stars

Abstract

During the evolution of hot stars, the equatorial rotational velocity can approach its critical value. Further increase in rotation rate is not allowed, consequently mass and angular momentum loss is needed to keep the star near and below its critical rotation. The matter ejected from the equatorial surface forms the outflowing viscous decretion disk. Models of outflowing disks of hot stars have not yet been elaborated in detail, although it is clear that such disks can significantly influence the evolution of rapidly rotating stars. One of the most important features is the disk radial temperature variation because the results will help us to specify the mass and angular momentum loss of rotating stars via decretion disks.