Wind may deflate search for habitable planets
Study suggests that stellar wind of M-dwarfs erodes atmosphere of planets in the habitable zone.
The hunt for habitable planets beyond the Solar System just became more difficult. A study posted today on the arXiv server suggests that the same factors that make planets near M-dwarf stars easy to probe for potential life also diminish the chances that life could actually exist on those planets.
Researchers have often cited the environs of M-dwarfs, a type of red dwarf star, as a relatively easy place to look for planets that might be habitable. The stars are the most common type in the Galaxy, and their small size and mass makes it easier to detect planets orbiting them and use starlight to probe the planets' atmospheres. M-dwarfs are cooler than the Sun, so their habitable zones — the region surrounding a star where water could exist as a liquid on a solid surface — are closer in than the Sun’s. Planets in that region therefore complete an orbit in less time than Earth takes to orbit the Sun, providing astronomers with more opportunities to study them.
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