Imagine a world bathed in the light of not one, but two suns! Astronomers have just unveiled an extraordinary discovery: a 'Tatooine-like' exoplanet, reminiscent of Luke Skywalker's home in Star Wars, that orbits two suns. This finding is a game-changer, offering an unprecedented glimpse into the formation and movement of planets around multiple stars. But, what makes this even more special? Let's dive in.
This newly discovered exoplanet is a behemoth, six times the size of Jupiter, yet remarkably young, forming a mere 50 million years after the dinosaurs went extinct. And here's where it gets really interesting: it orbits its twin stars more closely than any other directly imaged planet in a binary system. The odds of finding such a celestial body are incredibly slim, as directly imaging a planet outside our solar system is already a rare feat.
According to a study published in The Astrophysical Journal Letters, this exoplanet is six times closer to its suns than any previously discovered exoplanets. This proximity allows us to witness a fascinating cosmic dance, providing valuable insights into how planets can form and evolve in complex stellar environments.
Senior author Dr. Jason Wang of Northwestern University highlights the rarity of this discovery. "Of the 6,000 exoplanets that we know of, only a very small fraction of them orbit binaries," he explains. "Of those, we only have a direct image of a handful of them, meaning we can have an image of the binary and the planet itself. 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 star and the planet in the sky at the same time."
The exoplanet was found using data collected years ago. Dr. Wang, while a doctoral student, helped commission the Gemini Planet Imager (GPI), an instrument designed to capture images of distant worlds by blocking out the overwhelming glare of their stars. During the instrument’s lifetime, over 500 stars were observed, and only one new planet was found.
Nearly a decade later, study lead author Nathalie Jones revisited the data. By analyzing the data from GPI and cross-referencing it with data from the W.M. Keck Observatory, she noticed a faint object consistently following the motion of a star. This led to the confirmation of the exoplanet.
"Stars don’t stand still in a galaxy, they move around," Dr. Wang explains. "We look for objects and then revisit them later to see if they have moved elsewhere. If a planet is bound to a star, then it will move with the star."
To the team’s surprise, the planet was verified, which GPI captured in 2016, but it had gone unnoticed in earlier analysis. A European team independently found the same planet in its own reanalysis of the data, confirming Jones’ discovery.
While hotter than any planet in our solar system, it’s relatively cool compared to other directly imaged exoplanets. It’s located around 446 light-years away from Earth. The new exoplanet is also quite youthful, forming just about 13 million years ago. The research team was also struck by how close the exoplanet orbited around its host stars. The stars themselves tightly revolve around one another - taking just 18 Earth days to complete one revolution. The planet, however, takes 300 years to orbit the pair.
"You have this really tight binary, where stars are dancing around each other really fast," Dr. Wang notes. "Then there is this really slow planet, orbiting around them from far away."
The Northwestern team believes the binary stars formed first, followed by the planet. "Exactly how it works is still uncertain," Dr. Wang admits. "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 plans to continue studying the system to learn more about its formation and function. Jones is also continuing to reanalyze the old data. "There are a couple suspicious objects," she says. "But what they are, exactly, remains to be seen."
What are your thoughts on this discovery? Do you find the idea of a planet orbiting two suns as fascinating as we do? Could this discovery change our understanding of planet formation? Share your opinions in the comments below!
