Solar flare-related eruptions followed by long-lasting occultation of the emission in the He II 304 Å line and in microwaves

Plasma with a temperature close to the chromospheric one is ejected in solar eruptions. Such plasma can occult some part of emission of compact sources in active regions as well as quiet solar areas. Absorption phenomena can be observed in the microwave range as the so-called “negative bursts” and also in the He II 304 Å line. The paper considers three eruptive events associated with rather powerful flares. Parameters of absorbing material of an eruption are estimated from multi-frequency records of a “negative burst” in one event. “Destruction” of an eruptive filament and its dispersion like a cloud over a huge area observed as a giant depression of the 304 Å line emission has been revealed in a few events. One of the three currently known events is considered in this paper. One more of the events considered here is a possible candidate for such events.