SOLAR-FLARES CONTROLLED BY HELICITY CONSERVATION

The energy release in a class of solar flares is studied on the assump tion that during burst events in highly conducting plasma the magnetic helicity of plasma is approximately conserved. The available energy r elease under a solar flare controlled by the helicity conservation is shown to be defined by the magnetic structure of the associated promin ence. The approach throws light on some solar flare enigmas: the role of the associated prominences; the discontinuation of the reconnection of magnetic lines long before the complete reconnection of participat ed fields occurs; the existence of quiet prominences which, in spite o f their usual optical appearance, do not initiate any flare events; th e small energy release under a solar flare in comparison with the stoc kpile of magnetic energy in surrounding fields. The predicted scale of the energy release is in a fair agreement with observations.