Characteristics of the white-light source in the 1981 April 24 solar flare

The large white-light flare on 1981 April 24 (≡1358 UT) was very well observed at the hard X-ray, optical, and radio wavelengths. Energetic particles escaping from the Sun were detected in the interplanetary space and in the vicinity of the Earth. The flare had distinct impulsive and gradual phases and provided the best available measurements of the optical continuum in a solar flare. In this letter the authors present these observations and discuss their interpretation in terms of the energetics of the flare and the role of energetic electrons in the production of optical continuum emission.