According to new research, our Sun may have acted as a cosmic cannibal billions of years ago, swallowing a super-Earth planet during its infancy. The study suggests that traces of this violent event could still be hidden within the star’s interior, offering a solution to several persistent mysteries in solar physics.
Mutlu Yildiz of Ege University in Turkey and his colleagues theorize that the ingestion of a planet several times more massive than Earth left a lasting chemical imprint on the Sun. This hypothesis addresses notable differences between standard solar evolution models and actual observations, particularly regarding the depth of the solar convection zone, the sound-speed structure beneath it, and the Sun’s unexpectedly low lithium levels.
“By modelling the sun’s evolution and comparing the results with precise observations of its interior, we find that the ingestion of a super-Earth could help explain long-standing differences between standard solar models and observations,” Yildiz stated. He added that the team investigated whether these anomalies might share a common origin in the early chemical history of the star.
Young stars like the Sun are typically surrounded by protoplanetary disks—vast, flattened clouds of gas and dust. Because planets form from material chemically distinct from the surrounding disk gas, the researchers hypothesized that an early engulfment would leave a detectable signature inside the star.
Using advanced stellar evolution software, the team simulated various scenarios of planetary consumption. Their calculations identified a super-Earth with a mass five to ten times that of Earth as the best fit for the Sun’s current characteristics. “We thought planetary engulfment might affect the solar structure but did not expect the calculations to converge on such a specific super-Earth mass range,” Yildiz noted, calling the precise convergence one of the study’s most intriguing outcomes.
Previous studies have suggested that one or more super-Earths may have formed near Mercury’s orbit before migrating inward through the protoplanetary disk and crashing into the infant Sun. However, the new model does not strictly require total engulfment; it allows for the possibility that a planet was only partially consumed or that another mechanism is at play.
While the findings are currently based on computer modeling, the researchers believe the predicted structural and chemical fingerprints of such an event remain observable within the Sun. Yildiz emphasized that the next phase of research will focus on detecting these signatures independently.
The study was published on September 10 in the journal Monthly Notices of the Royal Astronomical Society.
Leave a Reply