Gamma ray measurements of the 1991 November 15 solar flare

The 1991 November 15 X1.5 flare is a well observed event. Comprehensive data from ground-based observatories and the Yohkoh, PVO, and Ulysses spacecrafts provide the basis for a contextual interpretation of gamma-ray spectra and light-curves from the Compton Observatory. In particular, spectral, spatial, and temporal data at several energies are necessary to understand the particle dynamics and acceleration mechanism(s) within this flare. X-ray images, Ca XIX data and magnetograms provide morphological information on the acceleration region, while gamma-ray spectral data provide information on the photon and particle energy spectra. Furthermore, time profiles in hard X-rays and gamma-rays provide valuable information on temporal characteristics of the energetic particles. We report the preliminary results of our analysis of the evolution of this flare as a function of energy (18.5 keV-2.5 MeV). These preliminary results, together with those from other observations may eventually assist in identifying and understanding the acceleration mechanism(s) taking place in this event.