Third Closest Neighbouring Star System Found 6 Lightyears Away

An astronomer announced today, March 11, that by scanning archival images that are publicly available and dating back to 1978, he has located a binary star system only 6.5 light years from Earth. The duo is the closest star system discovered since 1916 and has taken over the title for the third-closest star system to the sun. The archival material was recorded by NASA's Wide-field Infrared Survey Explorer (WISE).

Both stars in the new binary system are apparently "brown dwarfs," which was revealed by follow-up observation using the Gemini South telescope in Chile. Brown dwarfs are very cool and dim because they are too small in mass to ever become hot enough to ignite hydrogen fusion. As a result they resemble 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, Pa., 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."

The results will be published in the Astrophysical Journal Letters.

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 neighbor of the sun in 1839 at 4.4 light-years away, and the fainter Proxima Centauri, discovered in 1917 at 4.2 light-years.

Edward (Ned) Wright, the principal investigator for the WISE satellite at UCLA, said, "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."

Read the full news release from Penn state at https://science.psu.edu/news-and-events/2013-news/Luhman3-2013