Abstract:
The results of a study of the morphology of the large-scale filament structures of the sun and their relations with the distribution of the large-scale magnetic field on the solar surface are reported. A continuous filament which forms a closed circular contour has been seen on spectroheliograms, particularly during the maximum phase of the solar cycle. Their mean size seldom exceeds 10 degrees, while their lifetimes occasionally span several days. In the core of the H-alpha line, single filaments are seen connected with one another by a regular structure of dark chromospheric elements several tens of degrees in extent or at times by a conglomeration of absorption grains one to three degrees in length. Occasionally, prominences can be detected above filament channels. Some arches of the filament channel may elongate with an associated local increase in coronal intensity.
