Published online by Cambridge University Press: 14 August 2015
Magnetic field observations made utilizing a 1/7 Å birefringent filter for the FeI line at 5324 Å resolve magnetic field features comparable in scale to the Hα fine structure. Without exception, low lying filaments in the center of the disk coincide with boundaries of polarity change in the line of sight component of the magnetic field. Small filaments can be identified on a scale comparable to the Hα fibril structures. The arch filament systems are associated with areas of mixed polarity. ‘Satellite spots’ may sometimes be identified as small localized enhancements of magnetic field of both polarities around the perimeter of a sunspot.