Astronomers capture rare image of a Tatooine-like planet orbiting two stars

Most planets are never seen directly. Astronomers usually detect them indirectly by watching a star dim or wobble as a hidden planet tugs on it.

So when a telescope actually captures an image of a planet beyond our solar system, it stands out.

This time, the image revealed something even more unusual: a giant planet orbiting two stars at once.

The planet sits closer to its twin suns than any other directly imaged world known in a binary star system, clinging to a gravitationally complex environment once thought hostile to planet formation.

The find gives scientists a rare chance to study how planets behave and survive around pairs of stars, offering new insight into some of the most challenging planetary systems in the galaxy.

Planet chaos with two stars

Two stars don’t behave like one calm, steady anchor. They pull on each other. Their gravity tugs and shifts in ways that can make it harder for planets to form and harder for scientists to track what’s going on.

That’s why discoveries like this matter. They give astronomers a real-world system to study instead of a tidy textbook version.

This new find helps scientists watch how stars and planets orbit together in a complicated setup.

The discovery also gives astrophysicists a chance to test ideas about how planets form when more than one star controls the neighborhood.

A rare planetary snapshot

“Of the 6,000 exoplanets that we know of, only a very small fraction of them orbit binaries,” said Jason Wang, an assistant professor of physics and astronomy at Northwestern University and the study’s senior author.

Only a handful of those binary-orbiting exoplanets have been directly imaged, allowing astronomers to see both the pair of stars and the planet in the same system.

“Imaging both the planet and the binary is interesting because it’s the only type of planetary system where we can trace both the orbit of the binary stars and the planet in the sky at the same time,” he said.

“We’re excited to keep watching it in the future as they move, so we can see how the three bodies move across the sky.”

Blocking stars to see planets

The key tool behind this story is the Gemini Planet Imager, often shortened to GPI. It’s built for a specific job: help astronomers see faint planets next to blindingly bright stars.

The GPI tool does that by blocking the star’s glare and using adaptive optics to sharpen the view.

When Wang was a Ph.D. student, he helped commission GPI at the Gemini South telescope in Chile. The team ran a major survey, pointed the instrument at hundreds of stars, and tried to catch planets directly in the act of orbiting.

“During the instrument’s lifetime, we observed more than 500 stars and found only one new planet,” said Wang. “It would have been nice to have seen more, but it did tell us something about just how rare exoplanets are.”

Ruling out impostor stars

Nearly a decade after that first push, Jones went back through GPI observations taken between 2016 and 2019. She also cross-referenced them with data from the W. M. Keck Observatory.

That’s when Jones noticed a faint object that kept showing up in the right place, moving the way a real companion would move.

“Stars don’t stand still in a galaxy, they move around,” Wang said. “We look for objects and then revisit them later to see if they have moved elsewhere.”

Astronomers confirm a planet by checking whether it moves through space alongside its star over time.

If the object drifts independently, it is likely a background star passing through the field of view. But if the object keeps pace with the star, it is strong evidence of a true orbiting planet.

“We also look at the light coming off an object,” said lead author Nathalie Jones, a graduate fellow working with Wang’s team.

“We know what light from a star looks like versus what light from a planet looks like, we compared them and decided it better matched what we expect to see from a planet.”

Big, young, and far from Earth

The object turned out to be a planet that GPI had captured back in 2016, but nobody had confirmed it at the time.

This past summer, a European team independently found the same planet in its own reanalysis, backing up the result.

The planet itself is enormous, about six times the size of Jupiter. It sits roughly 446 light-years from Earth, and it formed around 13 million years ago, which makes it young by cosmic standards.

“That sounds like a long time ago, but it’s 50 million years after dinosaurs went extinct,” Wang said. “That’s relatively young in universe speak, so it still retains some of the heat from when it formed.”

The system’s timing is wild. The two stars whirl around each other fast, finishing one revolution in just 18 Earth days. The planet takes the slow route, needing 300 years to orbit both stars.

“You have this really tight binary, where stars are dancing around each other really fast,” Wang said. “Then there is this really slow planet, orbiting around them from far away.”

Studying planets in complex star systems

Researchers still don’t know exactly how this system formed, but they think the two stars likely formed first and the planet formed later around them.

“Exactly how it works is still uncertain,” Wang said. “Because we have only detected a few dozen planets like this, we don’t have enough data yet to put the picture together.”

The team wants more observations to track how the planet and the two stars move over time.

“We want to track the planet and monitor its orbit, as well as the orbit of the binary stars, so we can learn more about the interactions between binary stars and planets,” said Jones.

The team is continuing to comb through archival observations, because this planet showed how easily something real can hide in plain sight.

The full study was published in the journal The Astrophysical Journal Letters.

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