On the Origin of Optical Radiation During the Impulsive Phase of Flares on dMe Stars. II. Continuum and Line Radiation

Abstract

It is argued that not only the blue (at the brightness maximum) but also the red (in the slow decay phase) components of the optical continuum of powerful flares on dMe stars are formed near the photosphere. The possible appearance of HeI lines in the relaxation zones for the plasma to a state of thermal equilibrium (as a result of a rise in electron temperature owing to elastic collisions of electrons with atoms and ions) is noted (for sufficiently high speeds of a non-stationary chromospheric shock wave propagating toward the photosphere of the Sun and stars). A scheme is proposed for the positioning of the "layers" of plasma responsible for the generation of radiation in the white light continuum during the impulsive phase of powerful stellar flares.