[P-EM11] Exoplanet

[PEM11-P10] Impact evaluation on exoplanets considering the fluence of stellar high-energy particles.

*Yosuke Alexandre Yamashiki¹, Vladimir Airapetian², Tatsuhiko Sato³, Ayu Shirakashi⁷, Hiroyuki Maehara⁴, Yuta Notsu⁵, Takanori Sasaki⁶, Kosuke Namekata⁴ (1.Earth & Planetary Water Resources Assessment Laboratory Graduate School of Advanced Integrated Studies in Human Survivability Kyoto University, 2.NASA/GSFC , 3.JAEA, 4.NAOJ, 5.University of Colorado, 6.Department of Astronomy, Graduate School of Science, Kyoto University, 7.Faculty of Medicine, Kyoto University)

Keywords:Exoplanet, fluence, CME

The redefinition of the habitable zone (CHZ) around M-type stars was re-evaluated in the ExoKyoto exoplanet database, which compares different definitions of habitable zones, taking into account an assessment of stellar flare frequency and flare intensity on planetary boundaries, an assessment of estimated exposure on the surface of each planet, an assessment of the impact of atmospheric dissipation, and an assessment of CME fluence. The re-evaluation was attempted taking into account the evaluation of the impact of the flare frequency on the stellar surface, the evaluation of the estimated exposure on each planetary surface, and the evaluation of the CME fluence. In this study, for each of the 49 Earth-sized rocky planets in the habitable zone, we estimated the maximum flare energy that can occur once a year, the maximum flare energy, assuming an Earth-like atmosphere, based on the stellar rotation period, Rossby number and sunspot area estimated from Hα equivalent width observations of the host star with the Seimei telescope. The maximum flare energy that can occur once a year, the assumed exposure dose at 0.1 atmospheric pressure and 1 atmospheric pressure, and the atmospheric dissipation rate estimated from the assumed XUV of the star were estimated, respectively. As a result, the planet with the maximum exposure was GJ3323b, with a total annual exposure of 4,570 Sv at 1/10 bar, and 0.56 Sv at 1 bar. In contrast, Ross 128 b and LHS 1140b have annual total doses of 0.5 Sv and 0.1 Sv at 1/10 atmospheric pressure, respectively, confirming previous predictions that the stars are less active and fit habitable conditions. The atmospheric dissipation rate was estimated to be 528 times that of the Earth.