Gaia-4b, a planet twelve times more massive than Jupiter, orbits its star at a relatively cold distance, taking 570 days to complete a full orbit. Meanwhile, Gaia-5b, a brown dwarf 21 times the ...

Gaia-5b sits between planet and star, too small for fusion but too big to be a planet. This cosmic misfit challenges what we know about substellar objects. Astronomers examined 28 possible Gaia ...