9 hours ago
https://www.space.com/astronomy/sun/the-...e-evidence
EXCERPTS: Yildiz and colleagues theorize that the sun's act of planetary infanticide may help to explain differences between observations of the sun and what is predicted by models of stellar evolution. This includes the depth of the sun's convection zone and the so-called sound-speed structure just below the convection zone. It could also explain why the surface of the sun is depleted of the element lithium.
"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," Yildiz said. "We were interested in whether these problems might have a common origin in the early chemical history of the sun."
The researcher explained that young stars like the sun during its infancy are surrounded by vast flattened clouds of gas and dust called protoplanetary discs, where substantial amounts of material can move between the disc and the star.
"Since planets are made of material that is chemically different from the gas in the disc, we wondered whether the early engulfment of a planet could have left a chemical signature inside the young sun," Yildiz said.
[...] Their results found the best fit for the sun's current characteristics was the cannibalism of a planet between five and ten times the mass of the Earth, a type of planet called a super-Earth. This could explain the strange, unpredicted characteristics of the sun.
[....] "The earlier work proposed that a super-Earth could have formed and migrated into the young sun. Our paper asks whether the sun itself could still carry observable evidence that such an engulfment actually happened, and we believe it could," Yildiz concluded. "The next step is to see if these fingerprints can be independently detected... (MORE - missing details)
EXCERPTS: Yildiz and colleagues theorize that the sun's act of planetary infanticide may help to explain differences between observations of the sun and what is predicted by models of stellar evolution. This includes the depth of the sun's convection zone and the so-called sound-speed structure just below the convection zone. It could also explain why the surface of the sun is depleted of the element lithium.
"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," Yildiz said. "We were interested in whether these problems might have a common origin in the early chemical history of the sun."
The researcher explained that young stars like the sun during its infancy are surrounded by vast flattened clouds of gas and dust called protoplanetary discs, where substantial amounts of material can move between the disc and the star.
"Since planets are made of material that is chemically different from the gas in the disc, we wondered whether the early engulfment of a planet could have left a chemical signature inside the young sun," Yildiz said.
[...] Their results found the best fit for the sun's current characteristics was the cannibalism of a planet between five and ten times the mass of the Earth, a type of planet called a super-Earth. This could explain the strange, unpredicted characteristics of the sun.
[....] "The earlier work proposed that a super-Earth could have formed and migrated into the young sun. Our paper asks whether the sun itself could still carry observable evidence that such an engulfment actually happened, and we believe it could," Yildiz concluded. "The next step is to see if these fingerprints can be independently detected... (MORE - missing details)