Magnetospheric accretion on classical T Tauri stars
JF Donati, M Jardine, J Bouvier, et al

Abstract: Magnetic fields presumably play a key role in stellar formation, at a stage where newly formed stars are still surrounded by massive protostellar discs and actively accreting material from it. In this process, magnetic fields are supposed to link the inner disc rim to the stellar surface, with disc material flowing towards the star along field lines through discrete accretion funnels. Understanding the angular momentum history of solar-like low-mass stars thus require to unveil the details of the magnetospheric accretion process. , To reach this goal, one must retrieve the topology of the magnetic field at the surface of the accreting star, a task that only ESPaDOnS@CFHT (and NARVAL@TBL for the brightest targets) can achieve thanks to their spectropolarimetric capabilities, their wide spectral domains and their high throughputs. In this talk, we will present the first results obtained in this research topic with ESPaDOnS and NARVAL in the framework of a French-UK collaboration, and will outline how to extend it to obtain a more realistic description of magnetospheric accretion processes on young low-mass stars.