How long do celebrities live alone? For brown dwarfs — objects that straddle the boundary between the most massive planet and the smallest star — astronomers need to find more examples of their companions to find out. Using NSF NOIRLab’s Astronomical Data Laboratory science platform, ace citizen scientist Frank Kiwy has discovered 34 new ultracold dwarf binary systems near the sun, nearly double the number of known such systems.
A citizen scientist scoured NSF’s NOIRLab’s catalog of 4 billion objects, called NOIRLab Source Catalog DR2, to reveal brown dwarfs and their companions.His in-depth research led to the discovery of 34 ultracold dwarf binary systems, nearly double the number of previously known samples .
Brown dwarfs sit between the most massive planets and the smallest stars. Brown dwarfs largely resemble cooling embers by lacking the mass needed to sustain nuclear reactions in their cores. Their ambiguity and relatively small size make them difficult to identify. Data from sensitive telescopes has enabled the discovery of thousands of objects, but only a fraction of them have been identified as binary. The difficulty of observing these faint embers also means that astronomers still aren’t sure how often brown dwarfs have companion stars.
To help find brown dwarfs, backyard worlds: Planet 9 citizen science project astronomers have previously turned to a global network of more than 100,000 citizen volunteers who scrutinize telescope images to determine how subtle brown dwarfs are to background stars sports. Despite the power of machine learning and supercomputers, the human eye remains a unique resource when scouring telescope images for moving objects.
“The Backyard Worlds program fosters a diverse community of talented volunteers,” commented Aaron Meisner, NSF NOIRLab astronomer and co-founder of Backyard Worlds. “150,000 volunteers around the world participate in Backyard Worlds, with hundreds of ‘power users’ executing ambitious autonomous research projects.”
One such “super detective”—citizen scientist Frank Keevey—started a research project involving DR2, NOIRLab’s source catalog, a catalog of nearly 4 billion unique objects contained in the NOIRLab Astronomical Data Archive. of all public imaging data. By scouring the data for objects with the color of brown dwarfs, Kiwy was able to find more than 2,500 potential ultracold dwarfs in the archives.These were then scrutinized for signs of co-moving companions, yielding a total of 34 systems including a white dwarf or low-mass star and an ultracold dwarf companion . Kiwy then led a team of professional astrophysicists to publish the findings in a scientific paper.
“I love the Backyard Worlds: Planet 9 project! Once you get the hang of the general workflow, you can dig deeper into the subject,” comments Kiwy. “If you’re someone who’s curious and isn’t afraid to learn new things, then this might be the right thing for you.”
“This striking result clearly demonstrates that NOIRLab’s data archives reach far beyond the reach of professional astronomers,” noted Chris Davis, NSF’s NOIRLab program director. “The enthusiastic public can also participate in cutting-edge research and directly share the joy of cosmic discovery!”
Not only are these findings an inspiring citizen science story, they could help astronomers determine whether brown dwarfs are more akin to supermassive planets or small stars, and provide insights into how star systems evolve over time. It also showcases the continued excellence of scientists’ contributions to astronomy using astronomical archives and scientific platforms such as NOIRLab’s Astronomical Data Archive and the Community Science and Data Center’s (CSDC) Astronomical Data Lab.
“These discoveries were made by an amateur astronomer who conquered astronomical big data,” concludes Aaron Meisner. “The archives of modern astronomy contain a vast treasure trove of data and often contain significant discoveries just waiting to be noticed.”
 Previous samples included white dwarf plus ultracool dwarf (L dwarf) pairs separated by more than 150 astronomical units (au), and red dwarf plus L dwarf pairs separated by between 700 and 1800 AU. The astronomical unit (au) is the unit that astronomers originally chose to express the average distance between Earth and the sun: about 150 million kilometers or 93 million miles.
 The closest pair of dwarfs are physically only about 170 au apart, while the farthest pair are about 8500 au from each other.