Accretion of Pre-Main Sequence binaries

The magnetospheric accretion of classical T Tauri stars is now better understood. In these systems, the inner disc is truncated by the strong magnetic field of the star, forcing the material to leave de disc plane and free-falling onto the stellar surface following the magnetic field lines. However, this process is valid only for single stars, a companion or a circumbinary disc doubtless implies deviations from this scheme. In this talk, I will present a spectropolarimetric analysis of extreme cases of this situation: Eccentric binaries with equal-mass components accreting from a circumbinary disc. This study aimed to identify if the accretion of these systems can be interpreted as a single-like case with some deviations. We thus looked for signatures of magnetically driven accretion, along the rotation cycle of the components and the orbital motion. We concluded that a magnetically driven accretion is in place on these systems as well. However, the inner disc might be too distant to be reached by the components’ magnetic field, the materials are thus probably first brought closer by gravitational instabilities. In addition, we showed that the inter-cycle variations of the systems’ accretion are at least partly shaped by the magnetic field variations of the components. This work is the first stone of a broader project, aiming at characterizing these processes on a broader range of multiple systems, and including the eruptive variables.