Stellar flares may expand habitable zones around small stars

The search for life beyond Earth has traditionally focused on exoplanets orbiting sun-like stars, which is a G-type star. However, low-mass stars, which are designated as K-type and M-type stars, have rapidly become a target for astrobiology, primarily due to their much longer lifetimes. This also means the habitable zone (HZ), which is the distance from a star where liquid water could exist, is much smaller than our solar system’s HZ, and is referred to as the liquid water habitable zone (LW-HZ). In contrast, another type of HZ that involves a star’s ultraviolet (UV) radiation potentially enabling life-harboring conditions is known as UV-HZ.