91福利

The continuously growing number of discovered exoplanets and accumulation of data regarding their physical and orbital characteristics provides us with a broad material for the study of general principles and major trends of planetary evolution. It reshapes the whole field of “exoplanetology” from a vague speculative subject into a practical science, aimed at characterisation and understanding of the variety of discovered extraterrestrial worlds. Investigation and characterisation of exoplanetary magnetic fields and their role in evolution and habitability of planetary systems is closely connected with the study of the whole complex of stellar - planetary interactions, including stellar wind plasma flows, radiation, and stellar and planetary gravity effects. A key element in the proposed approach is to take into account self-consistently the upper atmosphere of a close-orbit giant exoplanet (a so-called hot jupiter) as an expanding dynamical gas layer heated and ionised by the stellar XUV radiation. Interaction of the outflowing plasma with the rotating planetary magnetic dipole field leads to the development of a current-carrying magnetodisk surrounding the exoplanet. The lecture will present our recent theoretical and experimental results regarding development of a generalized model of an exoplanetary magnetosphere with the consequent account of the effects of an expanding upper atmospheric material and formation of an equatorial magnetodisk. The outcomes of the performed theoretical, experimental, and numerical studies contribute to a deeper understanding of exoplanetary mass loss process and related problem of magnetospheric protection of hot jupiters.