Three-dimensional structure of a sunspot light bridge
Context. Active regions are the most prominent manifestations of solar magnetic fields; their generation and dissipation are fundamental problems in solar...
Towards an understanding of the Of?p star HD 191612: optical spectroscopy
We present extensive optical spectroscopy of the early-type magnetic star HD 191612 (O6.5f?pe-O8fp). The Balmer and HeI lines show strongly variable emission...
Truncated stellar discs in the near infrared. II. Statistical properties and interpretation
The results obtained in Paper I are used to study possible relationships between the truncation radius of stellar discs in the NIR and structural parameters of...
Results from a numerical and analytical investigation of the solution of a nonlinear axisymmetric diffusion equation for the magnetic field are presented for...
Twenty-year monitoring of the surface magnetic fields of chemically peculiar stars
Magnetic chemically peculiar stars of the main sequence can present rotational periods as long as many decades. Here we report the results of an observational...
The magnetic and kinematic configuration of sunspot penumbrae is investigated by performing an inversion of the Stokes profiles of three infrared lines at 1565...
Two new young, wide, magnetic + non-magnetic double-degenerate binary systems
We report the discovery of two, new, rare, wide, double-degenerate binaries that each contain a magnetic and a non-magnetic star. The components of SDSS J092646...
Two-dimensional solar spectropolarimetry with the KIS/IAA Visible Imaging Polarimeter
Context. Spectropolarimetry at high spatial and spectral resolution is a basic tool to characterize the magnetic properties of the solar atmosphere. Aims: We...
Two-fluid simulations of Rayleigh-Taylor instability in a magnetized solar prominence thread. II. Effects of collisionality
Solar prominences are formed by partially ionized plasma with inter-particle collision frequencies generally warranting magnetohydrodynamic treatment. In this...