By Nidhi Subbaraman

Just as Luke Skywalker watched two suns set from his sandy home planet Tatooine, a newly discovered planet called 2M1510 is circling its own twin stars some 120 light years away from our Solar System.

The trio is a rarity -- and when all of its unusual traits are considered together, it is unique.

It is a Tatooine-like binary system, with a single planet orbiting a double-sun . The system's twin stars are actually brown dwarfs -- what some scientists call "failed stars" because they never get hot enough to sustain nuclear fusion using hydrogen. And while planets generally circle a star on the same plane, 2M1510 navigates an orbit that is perpendicular to the paths of its twin brown dwarfs.

There are more than a dozen known planets that orbit two stars, but this is the only known binary brown dwarf system that hosts a planet orbiting at a right angle to the dwarfs' path, according to an account of the discovery published earlier this month in the journal Science Advances .

"Something weird is happening here," said Amaury Triaud, an astronomer at the University of Birmingham in the U.K. and one of the study authors. "Everything is as different as you could make it from the Solar System."

The research team spotted the brown dwarfs in 2018, but it wasn't until 2024, when the team was measuring the dwarfs to learn more about their orbit and size that the researchers came to suspect a third celestial body might be present.

While analyzing light measurements captured by the Very Large Telescope facility at the Paranal Observatory in Chile, they noticed that the direction of the dwarfs' orbits were shifting in a way that suggested a third object was influencing their movement.

"We weren't actually initially looking for any planets at all, and boom, we found one," Triaud said.

Because the researchers inferred the planet's existence, there is still a lot they don't know -- for instance, how big or far away 2M1510 is from the brown dwarfs.

The team expects its path and size could range from an orbit of 100 days for a planet up to five times the mass of Earth, to thousands of days for a planet with 15 times the mass of Jupiter.

The system is unusual "for a combination of reasons, any one of which would be strange -- but in combination, makes it extremely strange," said Keivan Stassun, an astronomer at Vanderbilt University who wasn't involved with the study.

In their study, the authors described detection methods that could help other astronomers observe the planet.

"We're expecting people will be able to confirm what we're saying in the not too distant future," Triaud said.

Write to Nidhi Subbaraman at nidhi.subbaraman@wsj.com

(END) Dow Jones Newswires

April 24, 2025 11:00 ET (15:00 GMT)

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