Transients as Determinants of Habitability

TL;DR

This paper discusses how stellar magnetic transients influence exoplanet habitability and highlights the potential of next-generation spectroscopic observatories to better characterize these phenomena.

Contribution

It proposes that advanced ground-based spectroscopy can significantly improve understanding of stellar activity and its effects on exoplanet environments.

Findings

Stellar magnetic activity impacts exoplanet habitability.

Next-generation spectroscopy can resolve transient stellar phenomena.

Improved characterization of space weather effects on planets.

Abstract

Stellar magnetic activity, manifested through spots (faculae and flares), fundamentally shapes the exoplanets' environments. For low-mass stars in particular, where most habitable-zone planets reside, the variable magnetic phenomena can dominate atmospheric chemistry, surface radiation levels, long-term atmospheric escape, and ultimately habitability. However, physical characteristics of these transients (e.g. energy and temperature) and their spectra remain ill-constrained due to limitations in cadence and magnitude access of current spectroscopic facilities. A next-generation 12-m class ground-based observatory equipped with integral-field spectroscopy (IFS) and multi-object spectroscopy (MOS) at R$\sim$4,000 and $\sim$40,000 offers a transformational opportunity to characterize stellar activity in the time domain across large samples of exoplanet host stars. Such a facility would enable simultaneous monitoring of continuum variability, chromospheric and coronal line diagnostics, and particle-accelerated flare signatures, resolving the physics driving space weather and quantifying its impact on planetary atmospheres.