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 …
Context. High-resolution spectropolarimetric observations provide simultaneous information about stellar magnetic field topologies and three-dimensional distributions of chemical elements. High- quality spectra in the Stokes IQUV parameters are …
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 …
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 …
Context. Chemically peculiar stars of the mercury-manganese (HgMn) type represent a new class of spotted late-B stars, in which evolving surface chemical inhomogeneities are apparently unrelated to the presence of strong magnetic fields but are …
The application of high-resolution spectropolarimetry has led to major progress in understanding the magnetism and activity of late- type stars. During the last decade, magnetic fields have been discovered and mapped for many types of active cool …
Context. A subclass of the upper main-sequence chemically peculiar stars, mercury-manganese (HgMn) stars were traditionally considered to be non-magnetic, showing no evidence of variability in their spectral line profiles. However, discoveries of …