Initial Results from the High Altitude Observatory White Light Coronagraph on Skylab - A Progress Report

The frequent, periodic observations by the white light coronagraph allow an examination of coronal variations over a broad range of temporal scales. Examples of the slowest and most rapid variations are presented. An example of extremely slow coronal variations is the gradual evolution - to a large equatorial streamer - in association with a marked decrease in solar activity, as the total magnetic flux in one hemisphere decreased. Another example is given of a long-lived quasi-stable coronal streamer, apparently associated with a stable filament channel; comparison of this streamer with coronal potential magnetic field computations show little correlation. The remainder of the paper summarizes some results on coronal transients - the most rapid variations observed. Characteristic mass and energies involved in mass ejection transients, their temporal and spatial distributions, their associations with surface phenomena and possible interplanetary signatures, and finally their role in coronal evolution are briefly noted.