For years, many astronomers thought planets around such stars, also called M dwarfs, were probably uninhabitable. Any worlds close enough to be in these relatively cool stars' "habitable zone" — the range of distances where liquid water can exist — were likely to be tidally locked, the thinking went, with one face freezing and the other at a boil. Red dwarfs also have a tendency to flare dramatically, doubling their brightness — and perhaps frying any nearby life forms.

Lately, though, some astronomers are rethinking such notions.

"There are a lot of advantages for looking for small planets around red dwarfstars," said John A. Johnson, an astronomy professor at Harvard University.

For one thing, red dwarfs are incredibly numerous, making up about 70 percent of the Milky Way's stellar population. Further, these stars are quite stable. Their superflaring period generally lasts for just 1 billion years or so, after which they settle down significantly.