Magnetic changes observed in a solar flare

Abstract

The authors present observations of a large impulsive flare (1B/M4, 1980 April 10). Observations of the microwave/hard X-ray burst show the time development of the impulsive energy release. Chromospheric (Hα) and photospheric (Fe I λ5324) filtergrams and photospheric (Fe I λ8688) magnetograms, intensitygrams, and velocitygrams show magnetic structure, flare emission, mass motion, and magnetic changes. These observations show that strong flare-wrought magnetic changes in the chromosphere and corona produce observable, sudden, permanent changes in the photospheric magnetic field. The observations also show that one of the changes was initiated by transient brightening in Fe I λ5324 and λ8688 in step with the impulsive energy release and filament eruption.