It’s Not Supposed To Be Like This: A Giant Planet Orbits A Small Star

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This artist's illustration shows the gas giant TOI-5205 b orbiting its M-dwarf (red dwarf) star. Astronomers expect to find massive gas giants around more massive stars than this, so this arrangement is a puzzle. It's not the only gas giant around a low-mass star, and collectively, they challenge astronomers' understanding of planet formation. Image Credit: Katherine Cain, Carnegie Science.

According to theory and models of planet formation, large gas giants should form around massive stars. That’s because massive stars have more massive protoplanetary disks. But astronomers have the opposite arrangement in some cases. New research highlights a massive gas giant on a close-in orbit around a low-mass M-dwarf, and it poses another challenge to our understanding planet formation.