Equatorial Wind Compression Effects Across the HR-Diagram
Session 21 -- Stellar Spectroscopy, Atmospheres, Models, Intrinsic Variables, Theory, Part I
Display presentation, Tuesday, June 13, 1995, 9:20am - 6:30pm

## [21.14] Equatorial Wind Compression Effects Across the HR-Diagram

R. Ignace, J.P. Cassinelli, J.E. Bjorkman (U. of Wisconsin-Madison)

Bjorkman \& Cassinelli (1993) developed a kinematical description for the supersonic winds from rotating stars. In their analytical model, material from the polar flow is deflected toward the equator resulting in an equatorial wind compression (the Wind-Compressed Disk model). Using a standard $\beta$-velocity law, we investigate the sensitivity of the wind distortion to the wind acceleration by varying the velocity exponent, $\beta$. As examples, we consider applications of the model to B[e] stars, Asymptotic Giant Branch stars, and novae. Using a shallow wind acceleration with $\beta=3$, equatorial to polar density contrasts of 3 or more (which we call Wind-Compressed Zone models) result in all of these stars for stellar rotations of only 10\%-20\% critical. Consequently, if the stellar winds are accelerated over radially extended regions, then moderate stellar rotations may be sufficient to explain the aspherical mass-loss observed in some members of these stellar classes.