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Outer Space

Astronomers Discover The Largest Known Planet That Orbits Two Suns

There's a famous scene near the beginning of Star Wars IV: A New Hope where Luke Skywalker is gazing introspectively at Tatooine's two suns setting over the horizon. Tatooine is an (albeit fictional) example of a circumbinary planet—one that orbits not one, but two stars. In June 2016, astronomers announced they had discovered the largest ever circumbinary planet. Its name? Kepler-1647b.

Related: Some Of The Strangest Exoplanets In Space

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This comparison of the relative sizes of several Kepler circumbinary planets shows how much larger Kepler-1647 b is than the others.

Eerily Familiar

Though other two-sun worlds have been discovered in the past, Kepler-1647b is substantially larger, roughly matching the size and composition of Jupiter. The planet has other similarities to those in our solar system as well. Its 4.4-billion-year age is about the same as Earth's, and each of its stars are around the same size as the Sun.

Related: "Saturn On Steroids" Has Massive and Seemingly Impossible Rings

We Finally Found You

Whereas a Jupiter-sized planet would ordinarily be pretty easy to spot with an advanced telescope, confirmation of Kepler-1647b took an unusually long time. Astronomers identify exoplanets by watching them pass in front of their home stars, and this planet's two-star system and its lengthy three-year orbital period made that particularly tricky.

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Watch And Learn: Our Favorite Content About Circumbinary Planets

Astronomers Find Largest Known Planet To Orbit Two Suns

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Key Facts In This Video

  1. Astronomers recently discovered the largest planet known to date to orbit two stars. 00:09

  2. It's located 3,700 light years away and is roughly the same age as Earth. 00:20

  3. It's located within the habitable range, but because it's a gas giant, life is unlikely to be present. 00:31

Ask An Astronomer: Can A Planet Have Two Suns?

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