Why brown dwarfs stay little ‘starlets’

Despite being numerous across the immensity of space, little "starlets" known as brown dwarfs are hard to spot because they are small and cool in temperature. (Credit: Enokson/Flickr)

A powerful laser is shedding light on why some of the most mysterious celestial objects in the solar system—brown dwarfs—fail to grow into stars.

Scientists have thought part of the answer may be in the physics of how dense plasmas merge inside them. Now, using the UK’s Science and Technology Facilities Council’s (STFC) Vulcan Petawatt laser, they have created “lumps” of plasma that mimic the conditions similar to those found deep inside brown dwarfs.

artist's concept of brown dwarf
This artist’s conception illustrates the brown dwarf named 2MASSJ22282889-431026. (Credit: NASA/JPL-Caltech)

Brown dwarfs bridge the gap between very low mass stars and planets and share characteristics with both, researchers say. Despite being numerous across the immensity of space, the little “starlets” are hard to spot because they are small and cool in temperature.

[This star buzzed our solar system 70,000 years ago]

Scientists were able to build up a profile of how dense plasmas form inside brown dwarfs by measuring the x-rays emitted from these objects. Their findings are published in the journal Nature Communications.

“Brown dwarfs are really difficult to observe because they are cool and our atmosphere absorbs the emissions from cool objects,” says Nigel Woolsey, professor of physics at the University of York.

“One of the issues you have in brown dwarfs with dense matter is how this material comes together and how hot it gets. This basic research is furthering our understanding of matter in extreme environments and furthering our understanding of exotic objects.”

Researchers from the University of Oxford, the University of Nevada, Instituto Nazionale di Optica, and Queen’s University Belfast contributed to the work.

Source: University of York