Mass ejection phenomena are common events to all astrophysical objects. In fact, star evolution and mass lose rates are so intimately related that they can be considered as two approaches of the same phenomenon. Within the framework of the compressible MHD, our group studies the continuous expansion of the outer shells of early type stars - stellar winds - and processes related to magnetized, rapidly rotating plasma outflows pushed away by the radiative force acting against the gravity force.

Plasma parameters span a wide range of collisionality in the solar wind. While the wind being accelerated in the lower corona can be described by the MHD equations, the distribution functions of the various species deviate strongly from Maxwellian as the wind evolves away from the Sun. It is therefore necessary to study the heat transport problem from a kinetic point of view.

We have solved the Fokker-Planck equation including a radially divergent magnetic field. We have obtained a nonlocal expression for the electronic heat flux containing a delocalization factor which interpolates smoothly between the classical Spitzer law for the collisional regime and the free-streaming formula for the so-called collisionless region (6-7 solar radii).