In a first-of-its-kind discovery in nearly a century, NASA scientists have found the third-closest star system to the Sun - located only 6.5 light-years away.
The pair of newly found stars is the closest star system discovered since 1916.
Both stars in the new binary system discovered by NASA's Wide-field Infrared Survey Explorer (WISE) are "brown dwarfs", which are stars that are too small in mass to ever become hot enough to ignite hydrogen fusion.
As a result, they are very cool and dim, resembling a giant planet like Jupiter more than a bright star like the Sun.
"The distance to this brown dwarf pair is 6.5 light-years - so close that Earth's television transmissions from 2006 are now arriving there," said Kevin Luhman, an associate professor of astronomy and astrophysics at Penn State University, University Park, and a researcher in Penn State's Center for Exoplanets and Habitable Worlds.
"It will be an excellent hunting ground for planets because the system is very close to Earth, which makes it a lot easier to see any planets orbiting either of the brown dwarfs," Luhman said in a statement.
The star system is named "WISE J104915.57-531906" because it was discovered in an infrared map of the entire sky obtained by WISE.
It is only slightly farther away than the second-closest star, Barnard's star, which was discovered 6 light-years from the Sun in 1916.
The closest star system consists of: Alpha Centauri, found to be a neighbour of the Sun in 1839 at 4.4 light-years away, and the fainter Proxima Centauri, discovered in 1917 at 4.2 light-years.
"One major goal when proposing WISE was to find the closest stars to the Sun. WISE J1049-5319 is by far the closest star found to date using the WISE data, and the close-up views of this binary system we can get with big telescopes like Gemini and the future James Webb Space Telescope will tell us a lot about the low-mass stars known as brown dwarfs," Edward (Ned) Wright, the principal investigator for the WISE satellite at University of California, Los Angeles, said.
The study will be published in Astrophysical Journal Letters.
