The only known life in the universe lives on a mid-size rocky planet that orbits a mid-size yellow star. That makes our planet a bit unusual. While small rocky planets are common in the galaxy, yellow stars are not. Small red dwarf stars are much more typical, making up about 75% of the stars in the Milky Way. This is why most of the potentially habitable exoplanets we’ve discovered orbit red dwarfs.
All things being even, you would expect then that red dwarf planets are the ones most likely to harbor life. But all things aren’t equal. Red dwarfs can be much more active than Sun-like yellow stars. They can emit enormous solar flares and strong x-rays. And since red dwarfs are much cooler than the Sun, planets must orbit very close to them to be potentially habitable. All of this paints a grim picture for life on red dwarf planets. A red dwarf would likely strip the atmospheres of close planets, and fry any life those worlds might harbor. But a new study finds that things might not be as bad as we thought.1
The team used data from the Transiting Exoplanet Survey Satellite (TESS). While the primary goal of the TESS mission is to study exoplanets that transit their stars, the TESS survey also contains data on stellar flares. So the team looked for the stellar flares of red dwarfs. From this, they could determine the latitude of solar flares on the star. They found that the distribution of flares on red dwarfs is very different from that of our Sun.