Habitability of exoplanets orbiting flaring stars

Abstract

As of late 2025 there are about 70 exoplanets that meet the formal criterion of having equilibrium temperatures allowing the presence of liquid water and about 50 of them orbit M-stars, known for their strong chromospheric activity. Most of these stars are close to the Sun and the planet-to-star mass and luminosity ratios are advantageous, allowing for a more detailed follow-up than of planets orbiting hotter and more massive stars. Many more planets orbiting late-type stars are expected to be discovered by Gaia and PLATO in the following years. However, the lingering question remains whether the UV and X-ray emission, associated with the stellar activity, allows for complex life. A comprehensive study focused on properties of flaring exoplanet hosts and their activity, on a much larger scale than these few tens (soon to become hundreds) of stars with habitable planets is called for, to answer the question if such stars can harbor habitable planets. The proposed Wide Field Survey telescope is well suited for this study.