The limb flare of 1980 April 30 as seen by the hard X-ray imaging spectrometer

X-ray imaging of the limb event of 1980 April 30 shows that the flaring involved two distinct components: a pointlike component, which was the source of the initial hard X-ray burst and an extensive tongue reaching some 30,000 km above the limb. The tongue had a higher temperature than the other parts of the structure and seemed to be enhanced by energetic electrons that derived their energy from the initial source.