An international group of scientists from the United States, South Korean and Brazil found one of the oldest stars related to the population II. Red giant SPLUS J210428.01-004934.2 is at a distance of 16 thousand light years from the Earth and is characterized by ultra-low metal. An article of astronomers was published in The Astrophysical Journal Letters.
The star was identified as part of an astronomical view of the S-PHOCAL Universe Survey. It is located in the Stripe 82 region, which is located in the field of heavenly equator and covers an area of 300 square degrees. The results of the photometric analysis J2104-0049 showed that the star contains very few atoms heavier hydrogen. The concentrations of carbon, oxygen, nitrogen and other elements are less than in the sun, more than ten thousand times.
Such a low metallicity indicates that the red giant belongs to the population II. These are several generations of stars that were formed shortly after a large explosion, and their age is more than 10 billion years. They arose from the remains of the first stars who had no carbon. It was the death of stars of the population III, whose life expectancy has hardly exceeded a million years, led to the emergence of heavy atoms included in the stars of the following generations, including the stars of the population I, to which the sun applies.
According to the results, the simulation, the chemical composition of J2104-0049 is best due to the fact that it originated from the residues of the high-energy supernova solitary population of the population III, whose mass of 29.5 times higher than the mass of the Sun. At the same time, the models could not accurately reproduce the relatively high silicon content in J2104-0049, so scientists offer to search for more ancient stars with a similar composition to understand how they could form.