The surface magnetic activity of the weak-line T Tauri stars TWA 7 and TWA 25

ABSTRACT We present an analysis of spectropolarimetric observations the low-mass weak-line T Tauri stars TWA 25 and 7. The large-scale surface magnetic fields have been reconstructed for both using technique Zeeman Doppler imaging. Our maps reveal predominantly toroidal non-axisymmetric stars. These reinforce wide range that recovered, particularly in pre-main sequence stopped accreting from (now depleted) central regions their discs. reconstruct large scale brightness distributions stars, use these reconstructions to filter out activity-induced radial velocity jitter, reducing RMS variations 495 32 m s −1 25, 127 36 7, ruling presence close-in giant planets 7 velocities provide example a case where mimic Keplerian signal is uncorrelated with spectral activity indices. This shows usefulness longitudinal field measurements identifying variations.