3 planets orbiting dwarf star prime spots to search for life

CAPE CANAVERAL, Fla. — Astronomers searching for life beyond our solar system may need to look no farther than a little, feeble nearby star.

A Belgian-led team reported Monday that it’s discovered three Earth-sized planets orbiting an ultra-cool dwarf star less than 40 light-years away. It’s the first time planets have been found around this type of star — and it opens up new, rich territory in the search for extraterrestrial life.

Because this star is so close and so faint, astronomers can study the atmospheres of these three temperate exoplanets and, eventually, hunt for signs of possible life. They’re already making atmospheric observations, using NASA’s Spitzer Space Telescope. The Hubble Space Telescope will join in next week.

Altogether, it’s a “winning combination” for seeking chemical traces of life outside our solar system, said Massachusetts Institute of Technology researcher Julien de Wit, a co-author of the study, released by the journal Nature.

The star in question — named Trappist-1 after the Belgian telescope in Chile that made the discovery — is barely the size of Jupiter and located in the constellation Aquarius.

Cool dwarf stars that emit infrared light, like Trappist-1, make it easier to spot potential worlds.

The two inner exoplanets take between 1.5 and 2.4 days to orbit the Trappist-1 star. The precise orbit time of the third planet is not known, but it falls somewhere between 4.5 days and 73 days. That puts the planets 20 times to 100 times closer to their star than Earth is to our sun, said Michael Gillon, one of the lead study authors.