Effect of rapid mass accretion onto the low-mass main sequence stars

I investigated the effect of mass accretion on low-mass main sequences stars, taking into account the heating of their photospheres by the UV and X-ray fluxes, generated by the infalling matter. The flux and the spectral shape of the UV and X-ray radiation reaching the photosphere is estimated by considering the processes taking place in the layers between the stellar surface and the shock front. The rough estimate indicates that the effectiveness of the heating is quite significant (at least one quarter of the kinteic energy of the infalling matter is transformed into the flux illuminating the photosphere). 22 refs., 6 figs. (author)