GoKawiilIt is thought the Sun may have engulfed a super-Earth-sized planet early in its history.
Now a new study has gone a step further by suggesting that such an event may have left behind detectable clues inside our star which could still be visible today.
This idea of a measurable signature or 'fingerprints' in the present-day solar interior was explored by research published today in Monthly Notices of the Royal Astronomical Society.
Professor Mutlu Yildiz, of Ege University in Turkey, said: "Our new study suggests that a planet several times more massive than Earth may have fallen into the young Sun and left a lasting chemical imprint deep inside it.
"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, including subtle changes in the Sun's internal structure and its depleted lithium abundance."
Researchers also found that such a world could survive its passage through the Sun's outer layers while losing very little mass, which suggests that planets may leave detectable fingerprints inside their host stars long after they have disappeared.
For many years, solar models based on the standard physics of stellar evolution have had difficulty reproducing some helioseismic observations simultaneously, particularly the sound-speed structure just below the convection zone and the depth of the solar convection zone.
At the same time, the Sun shows a strong and well-known depletion of lithium at its surface.
"We were interested whether these problems might have a common origin in the early chemical history of the Sun," Professor Yildiz explained.
"Young stars are surrounded by protoplanetary discs, where substantial amounts of material can move between the disc and the star.
... continue reading