Cosmic Cannibals: Red Dwarfs Reveal Planet-Devouring Signatures

Astronomers using Gaia-ESO data found six red-dwarf stars with unexpectedly high lithium in their atmospheres, a chemical that should be destroyed deep inside these stars. Because lithium should vanish quickly, its recent appearance signals the accretion of rocky planetary material, a phenomenon dubbed necroplanetology. The six stars (out of 318 examined in clusters) suggest roughly 3–10 Earth masses of planetary matter may have been swallowed, implying planet-devouring could occur in a notable fraction of red dwarfs depending on how long lithium lasts in their atmospheres. This finding offers a new way to study planet formation and early-system evolution.