Did the young Sun eat a super-Earth? Study hunts for the chemical scars

A new paper in Monthly Notices of the Royal Astronomical Society argues that our Sun may have swallowed a super-Earth-sized planet early in its life — and that the event could have left a chemical fingerprint still measurable in the star’s interior today. Using the MESA stellar-evolution code, Professor Mutlu Yildiz of Ege University modeled various accretion histories and found the data converge on a specific culprit: a rocky world roughly 5–10 times Earth’s mass that fell in while the Sun was young, losing little of its mass on the way down.

The appeal of the idea is that it resolves several long-standing discrepancies at once. Standard solar models have struggled to simultaneously reproduce key helioseismic measurements — notably the sound-speed structure just below the convection zone and the zone’s depth — while also accounting for the Sun’s unusually depleted surface lithium. Yildiz found that ingesting a chemically distinct planet reconciles these puzzles together, and he tested and set aside competing explanations involving the equation of state, opacity, and turbulent or convective mixing.

The work stops short of proof. Yildiz frames the engulfment as a scenario consistent with the evidence rather than a confirmed event, and the decisive test is whether the predicted structural and chemical signature can be independently detected through helioseismology or other observations. The study also feeds a broader question in planetary science: why super-Earths are common around other stars but absent from our own system — one possible answer being that the Sun simply consumed its own.