Instabilities and mixing in stellar radiation zones
The standard model of stellar structure is unable to account for various observational facts,and there is now a large consensus that some extra mixing must occur in the radiation zones. The possible causes for such mixing are briefly reviewed. The most efficient among them is probably the shear-turbulence generated by the differential rotation,which itself results from the transport of angular momentum that can be mediated through the large-scale circulation induced by structural adjustments or by the applied torques (stellar wind,accretion,tides). In solar-type stars this angular momentum transport is ensured mainly by internal gravity waves that are excited at the boundary with convection zones. Another cause of mixing manifests itself in the red giant phase,namely the thermohaline instability due to an inversion of the molecular weight gradient. The implementation of these processes in stellar evolution codes is giving rise to a new generation of stellar models,which are in much better agreement with the observational constraints.
Instabilities turbulence stars:evolution interiors rotation
Jean-Paul Zahn
LUTH,Observatoire de Paris,92195 Meudon,France
国际会议
The 252th Symposium of the International Astronomical Union(国际天文学联合会第252届研讨会)
海南三亚
英文
47-60
2008-04-06（万方平台首次上网日期，不代表论文的发表时间）