28.07.2019

Astronomers think they've spotted an alien planet with three suns on its horizon — but that still isn't the most interesting thing about the strange new world's sky.

Scientists found the world, which they've dubbed LTT 1445Ab, in data gathered by NASA's Transiting Exoplanet Survey Satellite (TESS). LTT 1445Ab orbits just one of the three stars, all of which are red dwarfs in the latter half of their lives, and the system is about 22.5 light-years away from Earth.

"If you're standing on the surface of that planet, there are three suns in the sky, but two of them are pretty far away and small-looking," co-author Jennifer Winters, an astronomer at the Harvard-Smithsonian Center for Astrophysics, told New Scientist. "They're like two red, ominous eyes in the sky."

From the TESS data, the scientists believe the planet is rocky, about a third larger than Earth and is at most about 8 times as massive as our home. It's awfully toasty on the surface — 320 degrees Fahrenheit (160 degrees Celsius) — and the planet circles one star of the triplet every 5 days.

But what's particularly special about it is something that scientists can't yet, but may soon be able to, characterize: its atmosphere. Because the stars in question are red dwarfs that are located reasonably close to Earth, and because the system is arranged so that the planet passes between stars and Earth, scientists may actually be able to get a glimpse of any gases surrounding the planet using telescopes based on Earth.

Astronomers can't quite take advantage of the opportunity yet, but it's exactly the sort of tantalizing prospect that TESS was designed to find. The instrument, which is halfway through its initial two-year survey of most of the sky, looks for planets with short years located around nearby, bright stars — the perfect targets for later instruments to peer at atmospheres.

Quelle: SC