New record-breaking brown dwarf is ‘purest’ and most massive

A record breaking brown dwarf, newly discovered by an international team of astronomers, is the most massive and ‘purest’ yet measured.

An artist's rendering shows an extremely pure and massive brown dwarf that astronomers estimate formed about 10 billion years ago. Photo by John Pinfield/RAS
An artist’s rendering shows an extremely pure and massive brown dwarf that astronomers estimate formed about 10 billion years ago. Photo by John Pinfield/RAS

SDSS J0104+1535 is located 750 light years away along the outskirts of the Milky Way galaxy, a region known as the halo. The brown dwarf and its stellar neighbors are the oldest in the galaxy. Astronomers estimate the mass formed 10 billion years ago.

Brown dwarfs are an intermediary group between planets and stars — much larger than gas giants, but too small to host nuclear fusion.

Spectral analysis of the brown dwarf suggests the mass’s composition is extremely pure. It is made up of 99.99 percent hydrogen and helium. It is also extremely large, the most massive yet discovered. The brown dwarf is 90 times the size of Jupiter.

The findings — detailed in the Monthly Notices of the Royal Astronomical Society — suggest a group of ancient and pure brown dwarfs are waiting to be found among the outer reachers of the galaxy. Until now, scientists didn’t believe primordial gas could yield brown dwarfs.

“We really didn’t expect to see brown dwarfs that are this pure,” lead researcher ZengHua Zhang, an astronomer at the Institute of Astrophysics in the Canary Islands, said in a news release. “Having found one though often suggests a much larger hitherto undiscovered population, I’d be very surprised if there aren’t many more similar objects out there waiting to be found.”

By Brooks Hays