Modelling stellar proton event-induced particle radiation dose on close-in exoplanets

Dimitra Atri

Research output: Contribution to journalArticle

Abstract

Kepler observations have uncovered the existence of a large number of close-in exoplanets and serendipitously of stellar superflares with emissions several orders of magnitude higher than those observed on the Sun. The interaction between the two and their implications on planetary habitability are of great interest to the community. Stellar proton events (SPEs) interact with planetary atmospheres, generate secondary particles and increase the radiation dose on the surface. This effect is amplified for close-in exoplanets and can be a serious threat to potential planetary life. Monte Carlo simulations are used tomodel the SPE-induced particle radiation dose on the surface of such exoplanets. The results show a wide range of surface radiation doses on planets in close-in configurations with varying atmospheric column depths, magnetic moments and orbital radii. It can be concluded that for close-in exoplanets with sizable atmospheres and magnetospheres, the radiation dose contributed by stellar superflares may not be high enough to sterilize a planet (for life as we know it) but can result in frequent extinction level events. In light of recent reports, the interaction of hard-spectrum SPEs with the atmosphere of Proxima Centauri b is modelled and their implications on its habitability are discussed.

Original languageEnglish (US)
Pages (from-to)L34-L38
JournalMonthly Notices of the Royal Astronomical Society: Letters
Volume465
Issue number1
DOIs
StatePublished - Feb 1 2017

Keywords

  • Planets and satellites: atmospheres
  • Planets and satellites: magnetic fields
  • Radiation mechanisms: non-thermal
  • Stars: flare

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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