Sun may have swallowed a super-Earth billions of years ago

A new study published in the Monthly Notices of the Royal Astronomical Society suggests that the Sun may have consumed a super-Earth-sized planet billions of years ago during its early history. Lead researcher Mutlu Yildiz of Ege University used stellar evolution software, MESA, to model various scenarios of planetary ingestion.

The research proposes that a planet with approximately 5 to 10 times the mass of Earth—specifically a model around 5.6 Earth masses—could have fallen into the young Sun. This event may explain several long-standing astronomical mysteries, including the Sun's notable deficiency of lithium on its surface and discrepancies between standard solar models and helioseismic observations regarding the Sun's internal structure and convection zone.

According to the study, the ingested planet could have survived its passage through the Sun's outer layers, leaving behind a lasting chemical “fingerprint” deep within the solar interior. This hypothesis also provides a potential explanation for why super-Earths, which are common in other planetary systems, appear to be absent from our own solar system.