Implications of modern observations on solar flare theory

Abstract

We present, in general, the solar flare phenomenon going through several aspects: a brief historical survey of solar flare observations, a general description of its observed characteristics and, finally, an account of the basic requirements set on solar flare models by the observational data. As a second step, we summarize some of our recent results on the observed character of energy release in a vast energetic and spatial range of events: flares, microflares and large scale brightening. The base of our analysis is the unique set of data provided by the Hard X-ray Imaging Spectrometer, that flew aboard Solar Maximum Mission satellite, and ground-based vector magnetograms from the Marshall Space Flight Center.