The mass ejection in the flare of March 12, 1989 on the basis of H-alpha filtergrams and spectrograms

The development of the flare 2B/M7.3 of March 12, 1989 is considered on the basis of series of simultaneous H-alpha filtergrams and spectrograms. The flare consists of two parts with different characteristics. In the main part of the flare an intense energy release occurred in the H-alpha line, with very wide profiles extended to more than 10 A. The other, peripheral part, in the shape of two-ribbon emission with a low-contrast filament between them, exhibits significantly less brightness. At the moment of maximum phase of the flare, a powerful mass ejection from the filament occurred. It is proposed that the mass ejection is caused by the instability of induced currents flowing along the filament and concentrating in thin magnetic flux tubes.