The effects of the tidal force and rotation on the velocity of stellar wind

The effects of tidal force and rotation on the velocity of stellar wind have been investigated. We have obtained the correct formula for the expansion of stellar wind. It is well known that the binary stars of Be type variable amount to more than 60% of their respective population, and their rotational velocity can be greater than 300 km s^–1. In such cases, we must take account of these effects.