New constraints on the future evaporation of the young exoplanets in the V1298 Tau system

TL;DR

This study uses X-ray observations to refine estimates of atmospheric evaporation in the young V1298 Tau exoplanets, revealing that most are unlikely to experience significant future atmospheric loss.

Contribution

It provides new constraints on the evaporation rates of young exoplanets in V1298 Tau, updating models with recent X-ray data and revising previous escape rate estimates.

Findings

Outer Jupiter-size planets are unlikely to evaporate significantly over Gyr timescales.

Inner planets' evaporation depends on their true masses, with lower masses potentially leading to more loss.

Massive planets can reach their final state early in their evolution.

Abstract

Transiting planets at young ages are key targets for improving our understanding of the evolution of exo-atmospheres. We present results of a new X-ray observation of V1298 Tau with XMM-Newton, aimed to determine more accurately the high-energy irradiation of the four planets orbiting this pre-main-sequence star, and the possible variability due to magnetic activity on short and long time scales. Following the first measurements of planetary masses in the V1298 Tau system, we revise early guesses of the current escape rates from the planetary atmospheres, employing our updated atmospheric evaporation models to predict the future evolution of the system. Contrary to previous expectations, we find that the two outer Jupiter-size planets will not be affected by any evaporation on Gyr time scales, and the same occurs for the two smaller inner planets, unless their true masses are lower than $\sim 40$ M$_\oplus$. These results confirm that relatively massive planets can reach their final position in the mass-radius diagram very early in their evolutionary history.