March 11, 2013
Closest Star System In A Century Found 6.5 Light Years Away
Brett Smith for redOrbit.com - Your Universe Online
Using data obtained from a NASA satellite, a Pennsylvania State University astronomer has identified the closest solar system to be found within the past 97 years.According to astronomer Kevin Luhman´s report in the Astrophysical Journal Letters, the newly identified system is a pair of brown dwarf stars and the third-closest system to 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," Luhman said. "It will be an excellent hunting ground for planets because it is very close to Earth, which makes it a lot easier to see any planets orbiting either of the brown dwarfs."
The new system was named “WISE J104915.57-531906" after the Wide-field Infrared Survey Explorer (WISE) satellite that made its discovery possible.
"One major goal when proposing WISE was to find the closest stars to the Sun,” said Edward Wright, the principal investigator for the WISE satellite.
“WISE 1049-5319 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,” he said.
In his report, Luhman described how he studied WISE satellite images from a 13-month period ending in 2011.
"In these time-lapse images, I was able to tell that this system was moving very quickly across the sky -- which was a big clue that it was probably very close to our solar system," Luhman said in a statement.
To investigate his suspicion, Luhman checked previous images over the past 35 years taken from the Digitized Sky Survey, the Two Micron All-Sky Survey, and the Deep Near Infrared Survey of the Southern Sky.
"Based on how this star system was moving in the images from the WISE survey, I was able to extrapolate back in time to predict where it should have been located in the older surveys and, sure enough, it was there,” Luhman said.
The Penn State astronomer was also able to determine the distance from Earth via a phenomenon known as parallax. Because of parallax, the system appears at different points in the sky during the course of Earth's orbit around the Sun. Luhman was also able to determine the temperature of the stars using the Gemini South telescope in Chile, which is capable of obtaining the light spectrum of an object.
"As an unexpected bonus, the sharp images from Gemini also revealed that the object actually was not just one but a pair of brown dwarfs orbiting each other," Luhman said.
The scientist noted that the new system´s proximity would put it on a short list of potential exploration sites for future space missions. Proxima Centauri, which was discovered in 1917, is the closest known system at 4.2 light years.
"It was a lot of detective work," Luhman said. "There are billions of infrared points of light across the sky, and the mystery is which one -- if any of them -- could be a star that is very close to our solar system."