Massive ‘Extinction-Level’ Flares Could Be Blasting at Proxima B

In August, news about the discovery of an Earth-like world that could potentially host life made headlines all over the world. This exoplanet, known as Proxima b, lies within Proxima Centauri, a red dwarf star just 4.2 light-years away from the Earth.

However, researchers have recently found that Proxima b could be frequently experiencing extinction-level "superflares" from its star Proxima Centauri, which might reduce the exoplanet's ability to sustain life, Space.com reports.

Recent research studies have found that exoplanets that lie very close to their stars - such as Proxima b, which orbits Proxima Centauri one-tenth of the distance between the sun and Mercury - could be subject to powerful flares coming from their host stars. These superflares are even more powerful than those that come from the Earth's sun.

To understand the effects of flares on exoplanets, research scientist Dimitra Atri from the Blue Marble Space Institute of Science in Seattle, Washington conducted computer simulations to model the interactions of a planet's atmospheres from the protons released during flares.

In the study, which was published in arxiv, Atri included in the simulations a wide range of flare strengths, atmospheric thickness, orbital distances from stars and strengths of the planet's magnetic fields. Atri found that if Proxima b had an atmosphere and magnetic field similar to Earth's, superflares will not have a significant effect on the planet.

But if Proxima b has a thinner atmosphere and weaker magnetic field, it could likely be experiencing destructive doses of radiation from Proxima Centauri's superflares.

"I would say that it is too premature to call Proxima b habitable," Atri said in an interview with Space.com. "There are many factors that would decide whether such a planet can sustain a biosphere. More data will help clarify the situation."

The research also highlights the importance of significant planetary magnetic field and good atmospheric shielding in determining the habitability of a planet as far as stellar flares are concerned. "With these two factors, even the most extreme stellar flares will not have much impact on a primitive biosphere," Atri said.

Atri is also conducting more research to see how different microbes respond to high doses of radiation. "I think that would tell us a lot about potential life on planets such as Proxima b," Atri said.