V830 Tau: An X-ray Bright T Tauri Star Hosting a Hot Jupiter

High-precision measurements have detected a giant Jupiter-like planet orbiting the T Tauri star V830 Tau in a tight 4.9 day orbit. The age of V830 Tau is ~2 Myr making this the youngest hot Jupiter exoplanet system detected so far. V830 Tau was detected as a bright X-ray source far off-axis in a previous XMM-Newton observation. The star has already shed its disk and the hot Jupiter is exposed to direct X-ray (and EUV) radiation from the star. We propose to obtain a HETG grating observation of V830 Tau to estimate the heating rate of the planet's outer atmosphere and the evaporative mass-loss rate. Estimates of atmospheric mass loss are crucial to understanding how hot Jupiters evolve and V830 Tau offers an exceptional opportunity to obtain a grating spectrum of the host star.