A worldwide group of volunteer sky watchers has helped scientists make one of the biggest discoveries of nearby brown dwarfs ever recorded.
Through NASA’s citizen science project, Backyard Worlds: Planet 9, volunteers have found more than 3,000 previously unknown brown dwarfs over the past decade, nearly doubling the number known to astronomers.
Brown dwarfs are strange objects that are too large to be planets but too small to become true stars.
They are often called “failed stars” because they never gain enough mass to start the nuclear reactions that make stars shine brightly.
Most are about the size of Jupiter, but much heavier.
Even though brown dwarfs are common in our galaxy, they are difficult to find because they give off very little light. Scientists estimate there may be one brown dwarf for every three or four stars near our sun.
The discoveries were announced in a new paper led by astronomer Adam Schneider from the U.S. Naval Observatory. The study was published on the arXiv preprint server and includes contributions from about 200,000 volunteers from around the world.
Many of the volunteers carefully searched through infrared images collected by NASA’s retired WISE space telescope and its follow-up NEOWISE mission. Using the Zooniverse citizen science website, volunteers compared images taken over a 16-year period to spot faint objects slowly moving through space.
Some participants even created their own computer tools to help analyze the data more efficiently.
The new discoveries are already helping scientists learn more about the hidden population of brown dwarfs in our galaxy.
Among the findings are several extremely rare objects, including ultra-cool brown dwarfs and unusual “extreme T subdwarfs.” Researchers also identified one brown dwarf that may produce aurora-like light displays similar to the northern lights seen on Earth.
The discoveries are helping astronomers better understand how stars and planets form and how matter is distributed throughout the Milky Way.
For many volunteers, the project became more than a hobby. Volunteer Walter Ruben Robledo from Córdoba, Argentina, said he deeply appreciated being recognized for the team effort.
Another volunteer, Mayahuel Torres Guerrero from Mexico City, said becoming a co-author on the scientific paper felt like a dream come true.
The project also shows how ordinary people can make real contributions to science. By working together online, volunteers helped uncover thousands of hidden worlds drifting quietly through our cosmic neighborhood.
