DATE2025.01.25 #Press Releases
Our solar system was born beside a dying massive star
-Dating a supernova explosion with aluminum-titanium cosmic nuclear clock-
Summary
A research team consisting of Associate Professor Tsuyoshi Iizuka, Associate Professor Yuki Hibiya and Graduate Student Satoshi Yoshihara of the University of Tokyo, and Senior Researcher Takehito Hayakawa of the Quantum Science and Technology Agency, has shown that the solar system was born in association with a massive star that underwent a gravitational collapse of its core to produce a supernova explosion.
Analysis of meteorites has shown that a short-lived radioactive isotope of aluminum, 26Al (half-life 0.73 million years), was present in the early solar system. However, the stellar origin of this 26Al remains unclear. This study shows that the origin of 26Al in the early Solar System is a core-collapse supernova explosion of a massive star, based on the finding that the variation in the abundance of 26Al in the early Solar System is correlated with the variation in the abundance of the stable titanium isotopes 46Ti and 50Ti. The research team also developed a new aluminum-titanium cosmic nuclear clock, which showed that the supernova explosion occurred less than 100 light-years from the birthplace of the Solar System, about 0.9 million years before the formation of the oldest meteorite in the Solar System (see figure). In the future, the application of this clock for dating of various meteorites is expected to advance our understanding of the planet formation process.
Figure: Schematic timeline of solar system formation and evolution
The solar system was formed by the gravitational collapse of a parental molecular cloud. The parent molecular cloud was contaminated by 26Al, 46Ti, and 50Ti ejected from the core-collapse supernova (CCSN) explosion of a nearby massive star. Analysis of meteorites shows that the outer region within the disk around the proto-sun contained more supernova ejecta relative to the inner region. Eventually, the terrestrial planets formed in the inner region of the disk, whereas the giant planets in the outer region.
Related links:QST, Research Center for Advanced Science and Technology, the University of Tokyo
Journals
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Journal name The Astrophysical Journal LettersTitle of paper