Using the American space agency's space telescope, called the Wide Field Infrared Survey Explorer, to sweep the skies, researchers found that stars once thought to be much further away are much closer, the Daily Telegraph reported.
"Neighboring star systems that have been hiding in plain sight just jump out in the WISE data," said Ned Wright of the University of California, Los Angeles, the principal investigator of the mission.
In a release Friday, NASA said researchers had been looking for "Planet X," a hypothesized celestial body beyond the orbit of Pluto.
"The outer solar system probably does not contain a large gas giant planet, or a small, companion star," said Kevin Luhman of the Center for Exoplanets and Habitable Worlds at Penn State University in University Park, Pa., author of a paper in the Astrophysical Journal describing the results.
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