The High-Energy Spectrum of the Young Planet Host V1298 Tau

TL;DR

This study constructs a comprehensive high-energy spectrum of the young star V1298 Tau using multi-instrument observations and models, providing a benchmark for understanding stellar activity and planetary irradiation in young solar-mass stars.

Contribution

It presents the first panchromatic spectral energy distribution of V1298 Tau from X-ray to ultraviolet, combining observations and models to characterize its high-energy emission.

Findings

V1298 Tau's high-energy spectrum is near the detection limit of current observatories.

The spectrum serves as a benchmark for stellar activity saturation stages.

Comparison of planetary irradiation with other systems enhances understanding of planetary atmospheres.

Abstract

V1298 Tau is a young pre-main sequence star hosting four known exoplanets that are prime targets for transmission spectroscopy with current-generation instruments. This work pieces together observations from the NICER X-ray telescope, the Space Telescope Imaging Spectrograph and Cosmic Origins Spectrograph instruments aboard Hubble Space Telescope, and empirically informed models to create a panchromatic spectral energy distribution for V1298 Tau spanning 1 to 100000 Angstroms. We describe the methods and assumptions used to assemble the panchromatic spectrum and show that despite this star's brightness, its high-energy spectrum is near the limit of present X-ray and ultraviolet observatories' abilities to characterize. We conclude by using the V1298 Tau spectrum as a benchmark for the activity saturation stage of high-energy radiation from solar-mass stars to compare the lifetime cumulative high-energy irradiation of the V1298 Tau planets to other planets orbiting similarly massive stars.