Holes in the Hα Eruptive Prominence Structure

摘要

The eruptive prominence observed on 27 May 1999 in Hα at Ondřejov Observatory is analyzed using image-processing techniques. To understand the physical processes behind the prominence eruption, heated structures inside the cold Hα prominence material are sought. Two local minima of intensity (holes), the first above and the second below the erupting Hα prominence, have been found in the processed Hα images. A comparison of Hα images with the SOHO/EIT and Yohkoh/SXT images showed: (a) the cold Hα prominence is visible as a dark feature in the EIT images, (b) the upper local minimum of intensity in the Hα image corresponds to a hot structure seen in EIT, (c) the lower minimum corresponds to a hot loop observed by SXT. The physical significance of the Hα intensity minima and their relation to the hot structures observed by EIT and SXT is discussed. The time sequence of observed processes is in favor of the prominence eruption model with the destabilization of the loop spanning the prominence. For comparison with other events the velocities of selected parts of the eruptive prominence are determined.