  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.
