Star Proxima Centauri's Powerful Flare Detected With ALMA

Space weather emitted by Proxima Centauri, the star closest to our sun, may make that system rather inhospitable to life after all.

Using data from the Atacama Large Millimeter/submillimeter Array (ALMA), a team of astronomers discovered that a powerful stellar flare erupted from Proxima Centauri last March. This finding, published in the Astrophysical Journal Letters, raises questions about the habitability of our solar system’s nearest exoplanetary neighbor, Proxima b, which orbits Proxima Centauri.

At its peak, the newly recognized flare was 10 times brighter than our sun’s largest flares, when observed at similar wavelengths. Stellar flares have not been well studied at the millimeter and submillimeter wavelengths detected by ALMA, especially around stars of Proxima Centauri’s type, called M dwarfs, which are the most common in our galaxy.

Artist impression of a red dwarf star like Proxima Centauri, the nearest star to our sun. New analysis of ALMA observations reveal that Proxima Centauri emitted a powerful flare that would have created inhospitable conditions for planets in that system.

Credit: NRAO/AUI/NSF; D. Berry

Artist animation of a red dwarf star similar to Proxima Centauri, the nearest star to our sun. New analysis of ALMA observations reveal that Proxima Centauri emitted a powerful flare that would have created inhospitable conditions for planets in that system.