1. Magneto-acoustic Effects in Stellar Winds

2. Introduction The flux of particles from stars is called stellar wind
Global parameters are dM/dt and vterminal
Different stellar models predict different values for the above parameters
Radiation pressure of the star is considered as a main source of stellar wind
Red giants problem

3. Alfven model
The wind is treated as a highly conductive fluid

4. The “frozen” field concept

5. Magnetic field lines

6. MHD equations

7. Linearization

8. Modes
If k and vA are perpendicular-longitudinal mode with ulong2=s2+vA2
If k and vA are parallel, there are two modes
Longitudinal with u=s (pure acoustic wave)
Transverse with u= vA (Alfven wave)

9. Mass loss rate of red giants

10. References
[1]Henry J.G.L.M. Lamers, Joseph P. Cassinelli “Introduction to Stellar Winds”,1999
[2]Peter A. Sturrock “Plasma Physics”,1994
[3]J.D.Jackson“Classical Electrodynamics”,1975