Citizen scientists recently helped direct astronomers to a pair of objects that straddle the line between planets and stars. These newly spotted substellar objects are brown dwarfs, which share many elements in common with stars. However, unlike stars these gaseous bodies don’t have enough mass to start nuclear fusion in their core, so they resemble planets more than stars.
©NASA/JPL-Caltech
These newfound brown dwarfs have very unusual compositions. They are the most planet-like brown dwarfs to be observed in the Milky Way’s oldest populations of stars. They also might help researchers learn more about planets outside the Solar System.