Billions of years ago, our solar system may have lost a massive planet because the young sun consumed it, according to a new study published in the journal Monthly Notices of the Royal Astronomical Society. The research offers a potential answer to a long-running question among astronomers regarding why our solar system lacks a super-Earth, a type of world that is otherwise common across the galaxy. Authored by Mutlu Yildiz, an astronomy professor and astronomer at Ege University in Turkey, the investigation used computer simulations to wind back the clock and evaluate the young sun with and without a swallowed planet.
Computer Simulations Suggest the Young Sun Engulfed a Missing Super-Earth
The models that incorporated a dense, rocky super-Earth—estimated to be about five to 10 times more massive than Earth and rich in heavy elements similar to Mercury—aligned closely with actual measurements of the sun. Yildiz dubbed the hypothetical celestial body Dev Dilek, with “Dev” meaning giant and “Dilek” traditionally associated with wishes directed toward Mercury. While earlier work proposed that a super-Earth could have formed and spiraled into the sun billions of years ago, this paper delves deeply into whether the sun retains evidence of that event. We believe it could,
Yildiz said in a statement.
Chemical Clues Pointing to a Solar Feast
The research tackles two separate puzzles in solar astronomy: the sun’s internal structure and its surface lithium levels. When the sun formed, it was made from the same material as meteorites and its surrounding gas cloud, meaning scientists can estimate how much lithium the newborn sun should contain. Today, however, the sun’s surface has over 100 times less lithium than expected. Because lithium atoms only break apart deep inside a star where temperatures are much higher, the missing element suggests something dragged it downward. The study indicates that an ill-fated planet brought in material poor in lithium but rich in heavier elements, and mixing that material into the sun’s outer layers helps account for the shortage.
Furthermore, the extra heavy elements buried just below the surface help models of the sun’s interior—including how sound waves travel and the depth of the churning outer layer—align more closely with real observations. Separate calculations tracked how a compact, iron-rich world behaves as it falls through hot solar gas, confirming that a rocky planet could realistically survive the plunge long enough to deliver its material to the correct depth. Although the findings do not definitively prove that the sun devoured a super-Earth, Yildiz noted that the calculations strengthen the physical plausibility of the scenario by matching a wide range of measurements better than any model without it. The next step is to see if these fingerprints can be independently detected,
Yildiz said.
