X-ray Irradiation of the Giant Planet Orbiting the T Tauri Star TAP 26

TL;DR

This study presents Chandra X-ray observations of the young star TAP 26, analyzing its variable X-ray emission to assess the impact on its orbiting planet's atmosphere, highlighting the importance of X-ray irradiation in planetary atmospheric models.

Contribution

First detailed X-ray characterization of TAP 26, providing data crucial for modeling the atmospheric effects on its close-in planet.

Findings

Star exhibited elevated X-ray emission with variability within hours.

X-ray flux and temperature decreased over days in subsequent observations.

Estimated X-ray ionization and heating rates for planetary atmosphere modeling.

Abstract

We present new Chandra X-ray observations of TAP 26, a ~17 Myr old magnetically-active weak-lined T Tauri star that has been reported to host a massive planet in a 10.8 day orbit. At a separation of a = 0.097 AU the planet will be exposed to intense X-ray and UV radiation from the star. The first observation caught the star in a state of elevated X-ray emission with variability on a timescale of a few hours and an X-ray temperature kTx ~ 2 - 4 keV. Two subsequent observations 5-10 days later showed slow variability and a lower X-ray flux and temperature (kTx ~ 1 keV). We characterize the X-ray emission and estimate the X-ray ionization and heating rates that will need to be incorporated into realistic models of the planet's atmosphere.