Superflares Spell Doom For Life on ‘Habitable’ Exoplanet – In the search for Earth-like worlds beyond the solar system, Kepler-438b seems to have it all. The planet is only about 12 percent bigger than Earth and orbits in its star’s so-called “habitable zone,” where temperatures are suitable for liquid surface water, a condition believed to be necessary for life.
But new research shows 438b’s parent star is probably a poor host. The red dwarf star is prone to violent outbursts, producing flares 10 times more powerful than anything ever recorded on our sun.
Along with the superflares, which occur every few hundred days, scientists suspect the star is spewing out high-energy particles, similar to solar storms known as coronal mass ejections, or CMEs. That plasma could be the planet’s doom.
“The likelihood of a coronal mass ejection occurring increases with the occurrence of powerful flares, and large coronal mass ejections have the potential to strip away any atmosphere that a close-in planet like Kepler-438b might have, rendering it uninhabitable,” astrophysicist Chloe Pugh, with the United Kingdom’s University of Warwick, said in a statement.
“With little atmosphere, the planet would also be subject to harsh ultraviolet and X-ray radiation from the superflares, along with charged particle radiation, all of which are damaging to life,” she noted.
The research is published in the Monthly Notices of the Royal Astronomical Society.
Source: news.discovery