Exoplanet Host Star Radiation and Plasma Environment

Autor(en)

J. L. Linsky, Manuel Güdel

Abstrakt

Radiation from host stars controls the planetary energy budget, photochemistry in planetary atmospheres, and mass loss from the outer layers of these atmospheres. Stellar optical and infrared radiation, the major source of energy for the lower atmosphere and planetary surfaces, increases slowly as stars evolve from the Zero-Age-Main-Sequence. Ultraviolet radiation, including the Lyman-α emission line that dominates the UV spectrum of M dwarf stars, controls photochemical reactions of important molecules, including H₂O, CO₂, and CH₄. Extreme ultraviolet and X-radiation from host stars ionizes and heats the outer layers of planetary atmospheres driving mass loss that is rapid for close-in Jupiter-like planets. The strength of the stellar UV, EUV, and X-radiation depends on stellar activity, which decays with time as stellar rotation decreases. As a result, the evolution of an exoplanet's atmosphere depends on the evolution of its host star. We summarize the available techniques for measuring or estimating the X-ray, EUV, and UV radiation of host stars with different spectral types and ages.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

University of Colorado, Colorado Springs

Band

411

Seiten

3 -

Publikationsdatum

2015

ÖFOS 2012

103003 Astronomie, 103004 Astrophysik

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/exoplanet-host-star-radiation-and-plasma-environment(c6c009a9-4b80-4533-8618-48c39280095d).html