Surprisingly Close Star System Discovered

Looks like astronomers may have new hunting grounds to search for exoplanets , and it’s  close–  in fact it’s just in our local interstellar neighborhood.  A new-found star system at only 6.5 light years away now ranks as the third nearest to our solar system and the closest to be discovered since 1917.

The new pair of stars are both classified as brown dwarfs– cool, dim objects that actually resemble planets more than stars. (Related: “Dimmest Stars in Universe Spotted?”)

While they do give off heat and have chemical properties like ordinary stars like our Sun, these weird objects  are often referred to as ‘failed stars’ since they don’t quite have enough mass that would allow them to be crushed by gravity so that thermonuclear reactions can ignite the hydrogen in their cores. (See also: Coldest Star Found—No Hotter Than Fresh Coffee)

The strange star system, dubbed unromantically WISE J104915.57-531906,  was stumbled upon by Kevin Luhman, an astronomer at Penn State University while studying a map of the entire sky stitched together from 13 months of observations obtained by NASA’s Wide-field Infrared Survey Explorer (WISE) satellite. What clued him in was that one particular star point appeared to have a rapid motion visible through time-lapse images.  (Related: First Pictures from WISE telescope)

Luhman decided to  extrapolate the star’s movement back in time and found that it was indeed captured but not identified by other surveys as far back as 1978.

“It was a lot of detective work,” Luhman said in a press statement. “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.”

While astronomical distances are vast, this star system is really quite nearby when it comes to our stellar surroundings , as Luhman points out in a press statement.

“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.

This diagram illustrates the locations of the star systems that are closest to the Sun. The year when each star was discovered to be a neighbor of the Sun is indicated. The new binary system is the third nearest system to the Sun, and the closest one found in a century. Credit: Janella Williams, Penn State University.
This diagram illustrates the locations of the star systems that are closest to the Sun. The year when each star was discovered to be a neighbor of the Sun is indicated. The new binary system is the third nearest system to the Sun, and the closest one found in a century. Credit: Janella Williams, Penn State University.

 

Comparatively the second-closest star, Barnard’s star, is 6.0 light years from the Sun while our nearest neighboring star system consists of Alpha Centauri at 4.4 light years, and its fainter companion 4.2 light year distant Proxima Centauri.

The proximity of this stellar pair, he says, may even make them favorable for us to send star-ships there one day.

“…in the distant future it might be one of the first destinations for manned expeditions outside our solar system.”

But for now the powerful eyes of ground based telescopes like the Gemini in Hawaii and Chile, and the future James Webb Space Telescope will search for any circling planets around these brown dwarfs.
The star system discovery will be published in a paper for Astrophysical Journal Letters.

 

Changing Planet

Andrew Fazekas, aka The Night Sky Guy, is a science writer, broadcaster, and lecturer who loves to share his passion for the wonders of the universe through all media. He is a regular contributor to National Geographic News and is the national cosmic correspondent for Canada’s Weather Network TV channel, space columnist for CBC Radio network, and a consultant for the Canadian Space Agency. As a member of the Royal Astronomical Society of Canada, Andrew has been observing the heavens from Montreal for over a quarter century and has never met a clear night sky he didn’t like.