In the menagerie of cosmic objects, brown dwarfs sit between stars and planets – not massive enough to start nuclear fusion but also not quite like planets. Researchers now report the discovery of nearly 100 of these objects in the solar neighborhood.
The feat was possible with the help of citizen scientists from the Backyard Worlds: Planet 9 project, who dedicated their spare time to investigate signals in the sky. Thanks to their work, over 1,500 new stars and brown dwarfs have been discovered. The new 95 brown dwarfs are among the coldest yet from that sample. The discoveries are reported in The Astrophysical Journal.
“These cool worlds offer the opportunity for new insights into the formation and atmospheres of planets beyond the solar system,” lead author Aaron Meisner, from the National Science Foundation’s NOIRLab, said in a statement. “This collection of cool brown dwarfs also allows us to accurately estimate the number of free-floating worlds roaming interstellar space near the Sun.”
The goal of the project is to discover the hypothetical Planet 9. Some scientists believe this world exists at the edge of the solar system, a few hundred times further out than the Earth is from the Sun. If so, it is likely cold and doesn’t reflect much sunlight, meaning the best way to look for it is with infrared observatories.
These infrared observatories are also good at spotting brown dwarfs, so while the hunt for Planet 9 continues, citizen scientists have pinpointed the position of many new celestial bodies. Without them, these new brown dwarfs would have remained yet-to-be-analyzed data points.
“It’s exciting these could be spotted first by a citizen scientist,” said Meisner. “The Backyard Worlds discoveries show that members of the public can play an important role in reshaping our scientific understanding of our solar neighborhood.”
So far, citizen scientists have combed through trillions of pixels in the hope of finding a new celestial body. Citizen scientist and paper co-author Jim Walla added: “It’s awesome to know that our discoveries are now counted among the Sun’s neighbors and will be targets of further research.”