Spectra of Solar Flares

Solar flares emit electromagnetic radiation within a very broad range of wavelengths, from 0.02 A (2 X 10-10 cm) up to more than 600 m (6X 104 cm). This may be continuous emission in some parts of the spectrum, line emission in others, or a combination of both. These different kinds of radiation, of course, come from different heights in the solar atmosphere and thus from different parts of the flare. This paper will discuss only the flare spectrum in the region accessible to the ground-based optical solar spectrographs, while other parts of the spectrum will be mentioned only if necessary for the understanding of the optical observa­ tions.