Imagine living in a world of triple sunsets.
The exoplanet LTT 1445Ab orbits one of the three suns, all of which are described as mid-to-late-life red dwarfs. “The planet transits the primary star in the system,” researchers explain, in a paper which is available on the scientific repository arXiv.
The planet is described as having a radius that is 1.38 R_Earth, which means that it is a little over a third larger than our planet.
File image – artist’s animation shows the view from a hypothetical moon in orbit around HD 188753 Ab, the first known planet to reside in a tight-knit triple-star system. (NASA/JPL-Caltech)
A red dwarf, or “M dwarf” in astronomical terms, is “the smallest, most abundant and longest-lived type of star in our galaxy,” according to NASA.
Scientists are intrigued by the discovery of the LTT 1445 Ab system. “It is the second nearest transiting exoplanet system found to date, and the closest one known for which the primary is an M dwarf,” they explain, in their study.
The paper has been submitted to the Astronomical Journal.
An artist’s depiction of the view from a moon’s surface of a gas giant and three suns.(Image: © NASA/JPL-Caltech)
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.”
Related: The Strangest Alien Planets (Gallery)CLOSEVolume 0%This video will resume in 6 seconds
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.