On plasma radiative properties in stellar conditions

The knowledge of stellar evolution is evolving quickly thanks to an increased number of opportunities to scrutinize the stellar internal plasma properties by stellar seismology and by 1D and 3D simulations. These new tools help us to introduce the internal dynamical phenomena in stellar modeling. A proper inclusion of these processes supposes a real condence in the microscopic physics used, partly checked by solar or stellar acoustic modes. In the present paper we rst recall which fundamental physics has been recently veried by helioseismology. Then we recall that opacity is an important ingredient of the secular evolution of stars and we point out why it is necessary to measure absorption coecients and degrees of ionization in the laboratory for some well identied astrophysical conditions. We examine two specic experimental conditions which are accessible to large laser facilities and are suitable to solve some interesting questions of the stellar community: are the solar internal radiative interactions properly estimated and what is the proper role of the opacity in the excitation of the non radial modes in the envelop of the Cepheids and the Be stars ? At the end of the paper we point out the diculties of the experimental approach that we need to overcome.