Backyard Astronomers Discover Brown Dwarf main content.

Backyard Astronomers Discover Brown Dwarf

by AMNH on

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When Backyard Worlds: Planet 9 was launched this February, the researchers behind it—including Museum astronomer Jackie Faherty—were hopeful that the citizen science tool would let amateur astronomers find new objects in the cosmos. They had no idea, though, how fast those new discoveries would arrive.

Just six days after the launch of the website in February, four different users alerted the science team to a curious object. Closer inspection using an infrared telescope confirmed the existence of a brown dwarf a little more than 100 light years away from the Sun. The details of the discovery were recently published in The Astrophysical Journal Letters.


An illustration of a purple planet-like object in a dark star field
This artist's concept illustrates a close-up view of a cool brown dwarf. Objects like this, drifting just beyond our solar system, have been imaged by NASA’s Wide-field Infrared Survey Explorer and could be discovered by Backyard Worlds: Planet 9.

“I was so proud of our volunteers as I saw the data on this new cold world coming in,” said Faherty. “It was a feel-good moment for science.”

Backyard Worlds—developed by NASA, the University of California-Berkeley, the American Museum of Natural History, Arizona State University, the Space Telescope Science Institute, and science crowdsourcing site Zooniverse—allows anyone with a computer and an internet connection to flip through images taken by NASA’s Wide Field Infrared Survey Explorer (WISE) spacecraft. If an object is close enough to Earth, it will appear to “jump” when multiple images taken of the same spot in the sky a few years apart are compared. The goal for the more than 37,000 volunteers already working on Backyard Worlds volunteers is to flag these moving objects for further investigation by the science team. 


Animated image shows an extremely close-up of objects in space, one of which is circled so you can see it's movement.
An animation showing the movement of a newly discovered brown dwarf across multiple images. 

One of the first of these investigations was prompted when Bob Fletcher, a science teacher in Tasmania, identified a very faint object moving across the WISE images. It was soon also flagged by three other citizen scientists from Russia, Serbia, and the United States. After some initial investigation by the research team, which originally called the object “Bob’s dwarf,” Faherty was awarded time on NASA's Infrared Telescope Facility in Hawaii, where she confirmed that it was a previously unknown brown dwarf just a few hundred degrees warmer than Jupiter. 

The authors say that sky surveys had missed this object because it’s too faint. All four volunteers are co-authors on the scientific paper announcing the discovery. To learn more about Backyard Worlds: Planet 9—including how you can take part—check out Faherty’s recent Facebook Live appearance.


While new brown dwarfs like this one are exciting finds, the research teams is hoping to make a find closer to home—a ninth planet in our solar system, whose presence is suggested by some data but remains undetected at present.

“It's possible that there is a cold world closer than what we believe to be the closest star to the Sun,” Faherty said. “Given enough time, I think our volunteers are going help to complete the map of our solar neighborhood.”

Want to help? Visit the project website to learn more about Backyards World: Planet 9 and start exploring.