Mashable reports on a newly discovered star that can serve as a time capsule for the some of the earliest days of the universe, made out of remnants of one of the first stars ever to wink on and then burn out:
Researchers spotted the extremely ancient and chemically primitive star in Pictor II, a satellite of a satellite: Pictor II is a dwarf galaxy that orbits the Large Magellanic Cloud, which, itself, circles the Milky Way. The star’s unusual makeup suggests it formed after a weak supernova of one of the original stars in the universe.
The star, known as PicII-503, bolsters the idea that small early galaxies like Pictor II shaped the chemical evolution of larger galaxies, like our own, when the larger ones eventually absorbed those relics. The discovery reveals a stage of cosmic history astronomers can’t directly see, even with powerful tools like NASA’s James Webb Space Telescope.
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“What excites me the most is that we have observed an outcome of the very initial element production in a primordial galaxy, which is a fundamental observation,” Anirudh Chiti, a Stanford University researcher who led the study, said in a statement.
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The recently discovered star, roughly 600,000 light-years away from Earth in the constellation Pictor, has remarkably low iron and calcium elements, much lower than practically any star known outside the Milky Way. By comparison, PicII-503 has less than 1-40,000th of the sun’s iron. But it also contains a relatively high amount of carbon.
This unusual mix suggests the star formed from gas polluted by just one very early — and very weak — star explosion. The idea is that a less powerful explosion would result in heavy elements like iron staying trapped in the dead star’s collapsed core, with lighter elements like carbon blasting into space. That would explain stars with low iron content but lots of carbon.
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You can read more about the discovery of PictorII-503 here, in Nature.