Kepler-438b is an Earth-like exoplanet whose atmosphere might have been shed away by vast quantities of harmful radiation emitted by its parent Red Dwarf star, Kepler-438.Researchers from the University of Warwick found that a treacherous stellar phenomenon called coronal mass ejection (CME) is connected with powerful flares and can strip off a planet's atmosphere.
Kepler-438b share similarities with Earth, including temperature and size. However, it is closer to its parent star than we are to the Sun. The superflares, which take place every several hundred days, has an energy equivalent of 100 billion megatons of TNT. Red dwarf Kepler-438's superflares are also 10 times more potent than the documented superflares of the Sun.
"It is likely that these flares are associated with coronal mass ejections, which could have serious damaging effects on the habitability of the planet," said lead researcher Dr. David Armstrong from the university's Astrophysics Group.
Chloe Pugh from the university's Centre for Fusion, Space and Astrophysics stressed that an atmosphere is vital for any form of life to develop. While flares alone do not carry significant and potential damages, the CME on the other hand, is a dangerous phenomenon linked to superflares that could strip atmospheres.
During a CME, high levels of plasma are thrown outward from the superflaring star. The likelihood of CME surges in relation to the rates of superflares. When a large CME shed away a planet's atmosphere, the planet does not only get exposed to harmful UV but also to X-ray and charged particle radiation.
Unlike Earth, Kepler-438b doesn't have a magnetic field that could protect it from the damaging flares. The superflares could also have been too strong, leaving the planet exposed to dangerous high levels of radiation making it uninhabitable.
Kepler-438b orbits around its parent star every 35.2 days. On Jan. 6, NASA announced that it's the Earth's closest exoplanet to date. NASA's Kepler Space Telescope discovered the exoplanet, along with many other exoplanets, it also regularly monitors over 150,000 stars found beyond our own solar system.
The research was published in the Monthly Notices of the Royal Astronomical Society.
