It is located in the Stripe 82 region
An international team of researchers, consisting of American, South Korean and Brazilian scientists, has discovered one of the oldest stars belonging to Population II. In an article by astronomers, published in The Astrophysical Journal Letters, it is said that the ultra-low metallicity red giant SPLUS J210428.01-004934.2 is located 16,000 light-years from Earth.
The star, located in the region Stripe 82, which is in the region of the celestial equator and covers an area of 300 square degrees, was identified as part of the S-PLUS astronomical survey. The results of photometric analysis of J2104-0049 led to the conclusion that it contains very few atoms heavier than hydrogen, and the concentration of carbon, oxygen, nitrogen and other elements is less than on the Sun, more than 10,000 times.
This low metallicity is reported to indicate that the red giant belongs to Population II. These are several generations of stars that formed some time after the Big Bang, and their age is more than 10 billion years, the publication claims. According to scientists from the United States, South Korea and Brazil, they arose from the remnants of the first stars that lacked carbon. According to the authors of the article, it was the death of population III stars, whose lifespan hardly exceeded 1 million years, that caused the appearance of heavy atoms that were included in the composition of stars of the next generations, including the stars of population I, to which the Sun belongs.
From the simulations, astronomers have concluded that J2104-0049’s chemical composition is best explained by the fact that it emerged from the remnants of a high-energy supernova single star population III, whose mass is 29.5 times the mass of the Sun. However, the models were unable to accurately reproduce the relatively high silicon abundance in J2104-0049, so the researchers proposed looking for older stars with a similar composition in order to understand the nature of their formation.
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