Abstract:
Magnetic stellar activity of exoplanet hosts can lead to the production of large amounts of
high-energy emission, which irradiates extrasolar planets, located in the immediate vicinity of
such stars. This radiation is absorbed in the planets’ upper atmospheres, which consequently
heat up and evaporate, possibly leading to an irradiation-induced mass-loss. We present a
study of the high-energy emission in the four magnetically active planet-bearing host stars,
Kepler-63, Kepler-210, WASP-19, and HAT-P-11, based on new XMM–Newton observations.
We find that the X-ray luminosities of these stars are rather high with orders of magnitude
above the level of the active Sun. The total XUV irradiation of these planets is expected to be
stronger than that of well-studied hot Jupiters. Using the estimated XUV luminosities as the
energy input to the planetary atmospheres, we obtain upper limits for the total mass- loss in
these hot Jupiters.
