2000A&A...362..615O

SU Aurigae is a T Tauri star that was well monitored during the MUSICOS 96 multi-site campaign. We present the results of the spectroscopic analysis of the circumstellar environment of this star, particularly of the Hα, Hβ, NaI D and HeI D3 line profiles. The signatures of modulated outflows and mass accretion events are analysed, as well as transient spectral features. We compute the cross-correlation function (CCF) of several pairs of (velocity bins in) spectral lines to better investigate the profiles' temporal variability. We found increasing time lags between the variability of HeI D3, NaI D and Hβ. We propose this may be understood in terms of azimuthal distortion of the magnetic field lines due to the different rotation rates of the star and the disk. We find the slightly blueshifted absorption features in Hα, Hβ and NaI D to be anti-correlated with the accretion flow signatures. We propose that the transient absorption features in the blue wings of Hα, Hβ and NaI D (signatures of mass outflows), and flare brightenings are related to the disruption of distorted magnetospheric field lines.