低質量星に対するCME のUV 放射量供給による生命存在領域の拡大

Abstract

It is very important to consider the amount of UV (ultra-violet) radiation for life existence and evolution because moderate UV radiation is necessary for the synthesis of biological compounds. Recently, life on the low mass stars has been suggested because of their long lifespan. However, these stars are out of ‘‘common region’’ between HZ (habitable zone) and UV-HZ, where the persistent life existence is expected because of lack of UV radiation. Then, this paper considers UV-HZ with the intensive supply of UV radiation from Coronal Mass Ejection (CME) and explores to increase the range of the common region around low mass stars. Then, we find the common region doesn’t always spread so much because CME size is proportion to the distance from a host star and the peak of UV luminosity depends on evolutionary phase of main sequence stars.