Proton Fluxes of Solar-Type Stars with Planetary Systems

Abstract

The previously developed method for estimating of the parameters of proton fluxes from flare energies for the Sun has been applied to data on the flare activity of solar-type stars. The obtained results will be used to estimate the radiation situation in a stellar system containing exoplanets. In our analysis, we have used catalog data on flares of solar-type stars obtained from observations with Kepler telescope. The empirical relations between the energy of X-ray flares and the proton flux for the Sun have been extended to the case of stellar flares, similar to what has been done previously in the case of coronal mass ejections (CMEs). The used method has had limitations caused by the extension of the solar analogy to other stars as well as the uncertainties that have arisen when applying scaling methods. It has been found that the characteristic values of the proton flux for solar-type stars can be one order of magnitude higher than the estimates for the Sun. Prospects for the development of alternative methods for estimating proton fluxes in the vicinity of stars of late spectral types have been discussed (for example, by studying the behavior of Si IV and He II emission lines in the far ultraviolet range).