  A radial velocity study by Donati et al. (2016) reported the detection of a
close-in giant planet in a 4.93 d orbit around the ~2 Myr old weak-lined T
Tauri star V830 Tau. Because of the stringent timescale constraints that a very
young host star like V830 Tau would place on hot Jupiter formation models and
inward migration mechanisms, independent confirmation of the planet's existence
is needed but so far has not been obtained. We present new Chandra X-ray
observations of V830 Tau. The Chandra observations in combination with previous
XMM-Newton observations reveal strong variable X-ray emission with an X-ray
luminosity spanning the range log Lx = 30.10 - 30.87 ergs/s. Chandra High
Energy Transmission Grating (HETG) spectra show emission lines formed over a
range of plasma temperatures from ~4 MK (Ne IX) to ~16 MK (S XV). At the
separation of the reported planet (0.057 au) the X-ray flux is ~10$^{6}$ -
10$^{7}$ times greater than the Sun's X-ray flux at Jupiter. We provide
estimates of the X-ray ionization and atmospheric heating rates at the planet's
separation and identify areas of uncertainty that will need to be addressed in
any future atmospheric models.
