On the quasi-homologous limb flares observed on 3 August 1981

Abstract

Five limb flares and a large surge, triggered obviously by the second flare, have been investigated on the basis of Hα on- and off-band heliograms and X-ray data obtained during a 6-hour period on 3 August 1981. In addition, in the vicinity of the flare location the sunspots and filaments were followed by observations over several of the former days too. Emphasis was layed on the ascending motion in the course of flare build-up and on the time evolution of the flare energy release using GOES observations in the case of the first and second flares. It was found that their ascending Hα flare kernels, which reached to a height of 20–25×10 3 km, have been the main center both the source and the starting points of flare loops and perhaps also the main site of the soft X-ray emissions.