A search for high energy gamma-rays from solar active regions

The Elliot model for solar flares predicts weak -ray emission from the flare region prior to large flares. A search has been made for such -radiation of energy > 50 MeV. The experiment was performed using balloon-borne detectors flown from an equatorial station during the 1967/1968 solar maximum. A number of small flares were observed, but no associated -rays were detected. A limit of 2.3 × 10⁴ photons/cm² s was placed on the emission from an importance 1N flare. The general lack of major solar activity during the period of the balloon flights precluded a test for the Elliot model.