H-Alpha Variability of V1298 Tau c

TL;DR

This study used high-resolution spectroscopy to investigate atmospheric escape in V1298 Tau c, finding no evidence of escaping material but detecting stellar activity that affects observations.

Contribution

First high-resolution spectral analysis of V1298 Tau c's atmosphere during transit, highlighting stellar activity's impact on atmospheric detection.

Findings

No strong evidence for atmospheric escape at H-alpha line

Detected variable stellar activity affecting observations

Broadband transit monitoring lacked sufficient precision

Abstract

The 23 Myr system V1298 Tau hosts four transiting planets and is a valuable laboratory for exploring the early stages of planet evolution soon after formation of the star. We observe the innermost planet, V1298 Tau c, during transit using LBT PEPSI to obtain high spectral resolution characterization of escaping material near the H-alpha line. We find no strong evidence for atmospheric material escaping at the orbital velocity of the planet. Instead, we find a deep stellar feature that is variable on the few percent level, similar to a previous observation of the planet and can be explained by stellar activity. We attempted to monitor the broadband optical transit with LBT MODS but do not achieve the precision needed to characterize the atmosphere or improve the ephemeris.