During his study of flare spectra with high dispersion instruments
Among other lines seen in emission are those of ionized metallic lines. the D, line of He I at A and some H lines of the Paschen series. D, line in small flares is seen a absorption. Lines of Fe II and those of low excitation Fe I are strongly brightened in flares. All these observations are consistent with highe: excitation in flares. Electron densities in the range 10 to 105 cm and electron temperatures in the range 17,000 K have been suggested by various authors to be the most favourable state under which the observed spectra are produced.
During his study of flare spectra with high dispersion instruments, Severny observed some fine structure granules which develop during the initial stage of the flares. These granules are short-lived with diameters - 400 km. Gas moves within granules with speeds as high km snd it greatly influences the wings of lines of flare spectrum.
Severny called these phenomena as "moastaches Moustaches are believed to be ditferent, fromU flares While flares are manifestations of release of large energies within a relatively short-time, moustaches are believed to be associated with small-explosion like events. Flares eject material with speeds ranging from a few hundred to as high as km s. The streaming material perturbs prominences and filaments.
The latter are sometimes destroyed or disrupted by flares, but strangely enough, reappear again after hours or days. Spectrographic studies indicate that large gaseous blobs which are manifestation of flare surges, rise high up into the solar atmosphere.
Undergoing steady deceleration due to solar gravity and ome down into the Sun again with approximately the same speed. Besides this Sun-bound mass motion, flares also eject streams of corpuscular radiation in a wide range of energies. These high-speed.
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