By means of numerical simulations , we investigate magnetized stellar winds of pre-main-sequence stars .
In particular we analyze under which circumstances these stars will present elongated magnetic features ( e.g. , helmet streamers , slingshot prominences , etc ) .
We focus on weak-lined T Tauri stars , as the presence of the tenuous accretion disk is not expected to have strong influence on the structure of the stellar wind .
We show that the plasma- \beta parameter ( the ratio of thermal to magnetic energy densities ) is a decisive factor in defining the magnetic configuration of the stellar wind .
Using initial parameters within the observed range for these stars , we show that the coronal magnetic field configuration can vary between a dipole-like configuration and a configuration with strong collimated polar lines and closed streamers at the equator ( multi-component configuration for the magnetic field ) .
We show that elongated magnetic features will only be present if the plasma- \beta parameter at the coronal base is \beta _ { 0 } \ll 1 .
Using our self-consistent 3D MHD model , we estimate for these stellar winds the time-scale of planet migration due to drag forces exerted by the stellar wind on a hot-Jupiter .
In contrast to the findings of Lovelace et al .
( 2008 ) , who estimated such time-scales using the Weber & Davis model , our model suggests that the stellar wind of these multi-component coronae are not expected to have significant influence on hot-Jupiters migration .
Further simulations are necessary to investigate this result under more intense surface magnetic field strengths ( \sim 2 - 3 kG ) and higher coronal base densities , as well as in a tilted stellar magnetosphere .