The initiation of a coronal transient

Abstract

The coronal transient/eruptive prominence event of August 5, 1980, observed by the Mauna Loa experiment system is analysed. This event provided data on the early development of the transient in the low corona between 1.2 and 2.2 solar radii, information that was not available when earlier attempts were made to explain transient phenomena. The transient's initial appearance in the form of a rising density-depleted structure, before the eruption of the associated prominence, is explained as an effect of magnetic buoyancy. The data suggest that this transient has a density depletion of 17% to 33% relative to an undisturbed corona which is approximately isothermal with a temperature of 1.5 x 10 to the 6th K and a coronal density of 1.0 x 10 to the 9th/cu cm at the base of the corona.