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There’s an iconic scene in the original Star Wars in which Luke Skywalker, played by Mark Hamill, watches a double sunset over Tatooine, the desert planet where he grew up. Planets with two suns are called circular planets, and the fictional Tatooine is the most famous of these worlds.
Circular planets also exist in reality, although they are rare. Until now, scientists have confirmed the existence of only 18 circular planets in the solar system Nearly 6,000 planets that have been recorded outside our solar system.
New paper A team of astronomers led by the University of New South Wales in Sydney, Australia, unveils a way to find elusive planets with two suns. Using this process, astronomers say they have already identified 27 potential planets around circumplanets.
“It’s important to be clear that these are all candidates, and the planets haven’t been confirmed yet,” said Margo Thornton, a Ph.D. at the University of New South Wales in Sydney. The candidate who led the study told CNET. “Follow-up feedback will certainly inform us.”
Eclipse watchers
Scientists have found that most of the planets we know are used Transit method. When a planet passes, or transits, between Earth and its star, we can see the shadow.
The decrease in starlight caused by a distant eclipse allows us to track exoplanets – planets outside our solar system – light-years away from Earth.
But astronomers can only use the transit method to find planets that pass between Earth and its star. If the planet’s orbit is outside our line of sight, we cannot see it.
“Our method does not have that limitation,” Thornton said. “It can find planets orbiting at all kinds of angles.”
The method researchers used to find new planets is called inverted precession. While this method has been used with binary stars before, the team says this is the first time it has been used in a large-scale search for new planets.
“These are the planets that all previous surveys have ignored,” Thornton said.
The transit method – where a planet crosses its star from our perspective, causing a small eclipse – is how most planets were discovered. Shown here in artist’s view.
Binary stars are a pair of stars orbiting each other. This new method examines the orbits of stars, which are revealed during a stellar eclipse, when stars line up so that one passes directly between Earth and the other.
When researchers detected a change in the eclipse schedule that couldn’t be explained otherwise, it suggested that a third object could be affecting the binary star’s orbits. This third body could be a spoofed planet.
“We’re not just adding to the list of known circular planets,” Thornton said. “We are opening a window to populations that were previously unreachable.”
Planets with two suns
The results are based on data collected previously Transit of the exoplanet survey satellite. NASA launched TESS in 2018 to search for new planets.
The closest candidate planet found by the team is about 650 light-years away, while the farthest planet is 18,000 light-years away. Researchers believe that this method could help astronomers find new planets in binary star systems.
The inverted motion method, shown here in an artist’s rendering, helps astronomers detect planets that may have missed transits.
“There’s a strange, wonderful feeling that comes with discovery: For a short time, we were the only people on Earth who knew these planet candidates existed,” Thornton said.
“Before the research was published, before anyone else saw the data, we were sitting there knowing that there were 27 possible worlds that no one had ever discovered before,” she said.