Abstract
The discovery of a terrestrial planet orbiting Proxima Centauri has led to a lot of papers discussing the possible conditions on this planet. Since the main factors determining space weather in the Solar System are the solar wind and cosmic rays (CRs), it seems important to understand what the parameters of the stellar wind, Galactic and stellar CRs near exoplanets are. Based on the available data, we present our estimates of the stellar wind velocity and density, the possible CR fluxes and fluences near Proxima b. We have found that there are virtually no Galactic CRs near the orbit of Proxima b up to particle energies ~1 TeV due to their modulation by the stellar wind. Nevertheless, more powerful and frequent flares on Proxima Centauri than those on the Sun can accelerate particles to maximum energies ~3150αβ GeV (α, β < 1). Therefore, the intensity of stellar CRs in the astrosphere may turn out to be comparable to the intensity of low-energy CRs in the heliosphere.
Highlights
Kepler discoveries of new extrasolar planets give great impetus for discussions of life conditions and possible conditions for habitable zone (see for ex. (Anglada-Escude et al, 2016; Garra o et al, 2016; Grießmeier et al, 2015, 2016) and references within)
It is clear that larger values of stellar wind velocity Garra o et al (2016) and shell should lead to stronger e ects of Galactic cosmic rays (GCR) modulation
Cosmic rays are an important factor of space weather determining radiation conditions near planets so it is essential to know radiation conditions near extrasolar planets
Summary
Kepler discoveries of new extrasolar planets give great impetus for discussions of life conditions and possible conditions for habitable zone (see for ex. (Anglada-Escude et al, 2016; Garra o et al, 2016; Grießmeier et al, 2015, 2016) and references within). Since the details of SCR spectrum is unknown to model the e ect of SCR one may use spectra of well known solar events (Atri, 2017) or average spectrum of solar proton events (Tabataba-Vakili et al, 2016) Another approach is to base on general physical principles (Struminsky & Sadovski, 2017) assuming solar-stellar analogies, which is not based on near Earth observations of solar cosmic rays. Such quality estimations by the order of magnitude can help to nd relevant values of parameters and compare them with solar one. Such evaluations should allow simplifying subsequent equations and numerical simulations
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
