SPHEREx Just Took the Fingerprints of Failed Stars Across Our Cosmic Neighborhood

Brown dwarfs are the black (or brown?) sheep of astronomy. They’re too big to be considered a traditional gas planet, but they are too small to have started nuclear fusion and made the full transition to star-hood. They also change dramatically over time, cooling, shrinking, and spinning faster as they age. Or at least we think they do - our models of the atmospheres of these celestial objects aren’t the best, according to a new paper in The Astrophysical Journal Letters by a team led by Zafar Rustamkulov at Caltech and NASA’s Jet Propulsion Laboratory.