Studies of the corona with the Solar Maximum Mission coronagraph/polarimeter

Abstract

The visible wavelength coronagraph/polarimeter on the Solar Maximum Mission (SMM) spacecraft is providing data on the flare processes manifested by coronal transients and on the degree of disruption of the evolutionary corona at the present epoch of the solar activity cycle. Among the first results are the discovery of frequent H-alpha emission from remnants of eruptive prominences in the outer corona and first observations of Fe XIV line emission to 3.2 solar radii. In the early stages of transients, cavities less dense than the ambient corona are occasionally found trailing the transient loops, with the loops being relatively thick and structureless. Some 22 transients have been identified in the initial survey of 52 days of observations; from this sample the preliminary conclusion is that transients during the SMM era (near solar maximum) occur over a wider range of latitude than, but with about the same range of speeds as, transients during the Skylab era (near solar minimum).