High Spatial Resolution Magnetograms of Solar Active Regions


Using the Universal Birefringent Filter at the Sacramento Peak Vacuum Tower Telescope we have obtained simultaneous observations of left and right circular polarization in various solar magnetic features with a resulting spatial resolution of 0’'.7 in the magnetograms. We describe the data reduction in some detail and discuss the various instrumental effects. In particular we show that seeing can create features in magnetograms. A penumbra near disk center shows small-scale features in the magnetogram which are associated with the bright filaments. Bright features in the umbra of a small spot exhibit considerable polarization signals. In a pore region opposite polarities are found within a few seconds of arc.

Astronomy & Astrophysics