A new study tied to NASA’s Backyard Worlds: Planet 9 project reports a major expansion of the known brown dwarf population. The project’s volunteer effort adds “over 3,000” new discoveries accumulated over roughly the past 10 years, bringing the total known number of brown dwarfs to nearly double what it was previously, according to the study. Brown dwarfs are objects made mostly of gas with sizes comparable to Jupiter but with masses below those of stars. They occupy a range between planets and stars, and they can be difficult to detect because they are relatively dim. The sources also note that brown dwarfs are relatively common in the solar neighborhood, with an estimated one brown dwarf for every three or four stars near the Sun. The findings credit volunteer classification work as a key driver of the increase in discoveries, while the underlying data come from astronomical surveys analyzed through the project.