stars: atmospheres

Magnetic field topology and chemical spot distributions in the extreme Ap star HD 75049

Context. Intermediate-mass, magnetic chemically peculiar (Ap) stars provide a unique opportunity to study the topology of stellar magnetic fields in detail and to investigate magnetically driven processes of spot formation. Aims: Here we aim to …

Are there tangled magnetic fields on HgMn stars?

Context. Several recent spectrophotometric studies failed to detect significant global magnetic fields in late-B HgMn chemically peculiar stars, but some investigations have suggested the presence of strong unstructured or tangled fields in these …

Magnetically Controlled Accretion on the Classical T Tauri Stars GQ Lupi and TW Hydrae

We present high spectral resolution (R ensuremath≈ 108, 000) Stokes V polarimetry of the classical T Tauri stars (CTTSs) GQ Lup and TW Hya obtained with the polarimetric upgrade to the HARPS spectrometer on the ESO 3.6 m telescope. We present data on …