TY  - JOUR
A1  - Poppenhäger, Katja
A1  - Ketzer, Laura
A1  - Mallonn, Matthias
T1  - X-ray irradiation and evaporation of the four young planets around V1298 Tau
T2  - Monthly notices of the Royal Astronomical Society
N2  - Planets around young stars are thought to undergo atmospheric evaporation due to the high magnetic activity of the host stars. Here we report on X-ray observations of V1298 Tau, a young star with four transiting exoplanets. We use X-ray observations of the host star with Chandra and ROSAT to measure the current high-energy irradiation level of the planets and employ a model for the stellar activity evolution together with exoplanetary mass-loss to estimate the possible evolution of the planets. We find that V1298 Tau is X-ray bright with log L-X [erg s(-1)] = 30.1 and has a mean coronal temperature of approximate to 9 MK. This places the star amongst the more X-ray luminous ones at this stellar age. We estimate the radiation-driven mass-loss of the exoplanets and find that it depends sensitively on the possible evolutionary spin-down tracks of the star as well as on the current planetary densities. Assuming the planets are of low density due to their youth, we find that the innermost two planets can lose significant parts of their gaseous envelopes and could be evaporated down to their rocky cores depending on the stellar spin evolution. However, if the planets are heavier and follow the mass-radius relation of older planets, then even in the highest XUV irradiation scenario none of the planets is expected to cross the radius gap into the rocky regime until the system reaches an age of 5 Gyr.
KW  - planets and satellites: atmospheres
KW  - planet-star interactions
KW  - stars: activity
KW  - stars: individual: V1298 Tau
KW  - X-rays: stars
Y1  - 2020
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/60146
SN  - 0035-8711
SN  - 1365-2966
VL  - 500
IS  - 4
SP  - 4560
EP  - 4572
PB  - Oxford Univ. Press
CY  - Oxford
ER  -