The peculiar solar flare of 1981 May 13

Abstract

Time-phase photographic observations with 0.7 Armstrong passband H-alpha filter and the morphological-cum-temporal behaviour of a large double solar flare which occurred on 1981 May 13 have been described. The two strands, constituting the flare, which initially appeared to cross each other, with a bright region at the location of crossing, later separated out, ultimately becoming roughly parallel. The mean separation between the two strands at various intervals of time have been measured. It is concluded that apart from the oscillating behaviour of the strands, there is shearing in them probably due to rotation of the footpoints.