Context. Imaging polarimetry is a powerful tool for imaging faint circumstellar material. It is a rapidly developing field with great promise for diagnostics of both the large-scale structures and the small-scale details of the scattering particles. …
Numerical simulations of solar surface convection have predicted the existence of supersonic horizontal flows in the photospheric granulation. Recently, the detection of such flows in data from the Hinode satellite was reported. We study supersonic …
Photometric light curves show apparent spot concentrations separated by 180 degrees in longitude that are commonly referred to as `active longitudes'. These spot concentrations have been observed to change in strength resulting in the `flip-flop' …
While diagnostic techniques based on the ordinary Zeeman effect (e.g. magnetograms) are almost ``blind'' to a turbulent magnetic field with mixed magnetic polarities within the spatial resolution element, the Hanle effect is sensitive to this domain …