Galactic cosmic ray propagation through M dwarf planetary systems

Quantifying the flux of cosmic rays reaching exoplanets around M dwarfs is essential to understand their possible effects on exoplanet habitability. Here, we investigate propagation Galactic as they travel through stellar winds (astrospheres) five nearby dwarfs, namely: GJ 15A, 273, 338B, 411 and 887. Our selected stars each have 1 or 2 detected all wind mass-loss rates constrained by Lyman-alpha observations. simulations use a combined 1D magnetohydrodynamic (MHD) Alfv\'en-wave-driven model ray transport model. We find that 887 fluxes comparable with Earth's at habitable zones. On other hand, 273 338B receive lower in All our sample, exception 15A c c, significantly than values observed Earth because orbit closer-in. The found here can be further used for chemical modelling planetary atmospheres. Finally, calculate radiation dose surface habitable-zone planet b, assuming it has an Earth-like atmosphere. This receives up 209 times less 15 MeV energy Earth. However, high-energy (~ GeV), difference only 2.3 smaller, which contributes b receiving significant 0.13 mSv/yr (40% annual surface).