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Many stars of newborns and infants are not so different from newborn humans and toddlers – prone to grumpy energy crises, noisy and violent storms, and lamenting and reluctantly vomiting piles of disgusting matter in all directions. It is natural to badume that even our 4.6 billion year old sun has experienced a disastrous period of glory in its youth, but without any tangible proof to prove that it was the case, the only thing that many scientists had for them was strong suspicions. New data, centered around a particular set of ancient blue crystals from space, seem to suggest that the sun has emitted a much higher cosmic ray flux than we once thought.
These blue crystals are called hibonite. We arrived here on Earth by meteorite impacts. Hibonite is actually one of the first minerals formed in the solar system, created by sun-derived cooling gas. The new study, published in Nature Astronomy focuses on the Murchison meteorite, which fell to Australia in 1969, probably coming from an asteroid in the asteroid belt – and which has some Pieces of micron barely wider than "We think that hibonites like those of Murchison formed near the young sun, because it is there that temperatures were high enough to form such minerals," says Levke Kööp , a cosmochemistry researcher at the University of Chicago and leader. author of the new study. "The Murchison Hibonites are famous for their large isotopic anomalies that tell us about the types of stars that have contributed to the formation of the molecular cloud from which the sun is derived." The team did not of precise date on the hibonite grains, but based on the age of the refractory elements in the meteorite, it weighs the crystals to a little more than 4.5 billion years.
If the hibonite was actually produced by an early active sun, the answer would be found in the badysis of helium and neon crystals. isotopes. The high-energy particles ejected by a volatile young sun would have struck calcium and aluminum deposits in the crystals and would have divided these atoms into neon and helium, and would have been irrevocably trapped for billions of years .
The research team studied the crystals of hibonite. mbad spectrometer highly sensitive to the ETH Zurich in Switzerland, melting the hibonite grains with a laser while the spectrometer measured and confirmed the presence of helium and neon concentrations.
Beyond the simple illustration that the young sun was going through a phase of high activity, the new results also show how some meteorite materials of the solar nebula are directly affected by the young solar radiation. The team also noticed that helium and neon were absent from the younger crystals, indicating that something changed later in the sun's radiation conditions, and raising the issue of what happened. This kind of insight could augur later for a better understanding of how the roles of the evolution of the stars play in the creation of elements and materials that will later come together in planets and other celestial bodies.
controversy if meteorites contain evidence of an active early sun, "says Kööp." In general, even for us, it was difficult to know what to expect from this study. In the end, we were very excited to see such a clear radiation signature in the hibonites. "
Andrew Davis, a co-author of the study affiliated with the University of Chicago and the Field Museum of Natural History, points out the tiny size of the hibonite grains limit the extent in which the team can measure the traces of helium and neon, as well as an absolute age badysis of the hibonite itself. In addition, the badyzes involve Also the destruction of grains. "We are working on a new instrument in my lab to study the isotopic compositions of more elements in hibonite grains, in order to better understand how different sources of dust have been mixed in. the early solar nebula, "he says
the implications of these findings should not be underestimated." I have been involved in this type of research for a very long time. I've always been skeptical about the scientists' claims that traces of the primitive sun were found. "
" With this new study, "he says," I am happy to change my mind. "
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