Astronomers had high hopes for Proxima b, a rocky world circling Proxima Centauri, the closest star to the Sun. However, a new study may have dashed those hopes by revealing that the star’s powerful flares could destroy the planet’s atmosphere.
Proxima Centauri is a small, cool red dwarf star, and its extremely close orbiting planet receives intense radiation from the star. The researchers used the Atacama Large Millimeter/submillimeter Array (ALMA) to detect 463 flares over 50 hours of observation. These powerful bursts release enormous amounts of energy and could potentially obliterate a planet’s atmosphere.
The study found that Proxima Centauri’s flares are much more frequent and extreme than previously thought, likely due to the star’s fully convective structure. This means that its entire structure moves like a boiling cauldron, creating a magnetic field that constantly jumbles and snaps, releasing energy in massive bursts.
The researchers used ALMA to detect these high-energy particles and gain insight into the properties of Proxima Centauri’s radiation. While Proxima b may be an irradiated rock, scientists will continue to search for rocky worlds with atmospheres around small red stars.
A new James Webb Space Telescope campaign aims to study a dozen nearby planets over the next two years to determine whether they can host air. The program is high-risk and high-reward, as discovering that none of these planets have atmospheres would be disappointing but also provide valuable insight into our planetary system’s uniqueness.
Source: https://mashable.com/article/proxima-centauri-exoplanet-atmosphere-habitability