Record-Setting Flare Spotted on the Nearest Star to the Sun.
Source: By Katherine Kornei, Eos/AGU.
Excerpt: As stellar neighbors go, the Sun is a pretty good one—it occasionally produces a sizeable solar flare, but mostly, it leaves Earth well enough alone. The Proxima Centauri solar system isn’t so lucky, however: Blasts of electromagnetic radiation from Proxima Centauri, the next nearest star to our own, can be potentially lethal to nearby planets. Researchers recently spotted the brightest stellar flare ever detected from Proxima Centauri. That flare might have contributed to stripping away the atmosphere of one of its planets, a roughly Earth mass world that potentially hosts liquid water on its surface. ...Destroyer of Atmospheres ...Proxima Centauri’s faintness stems from its low mass—it’s what astronomers refer to as an M dwarf star, defined as having a mass between roughly 10% and 50% the mass of the Sun. M dwarf stars are the most common stars in the Milky Way, but they come with a reputation, said Meredith MacGregor, an astronomer at the University of Colorado Boulder. “M dwarfs are vastly more active than the Sun.” That means they regularly emit stellar flares, blasts of electromagnetic radiation launched by their host star’s magnetic field. These streams of photons can be destructive, said MacGregor. When high-energy ultraviolet radiation collides with a planet’s atmosphere, it can disassociate molecules like water and ozone, splitting them into their constituent atoms. Some of those lighter atoms can then drift away and escape. “You can basically erode away the atmosphere of a planet,” said MacGregor....