Spanish astronomers announced the discovery of one of the oldest stars of our galaxy. Scientists believe that the object, dubbed J0815+4729, came to light only after 300 million years after the Big Bang, or about 13.5 billion years ago. For comparison, the age of the Sun is only 4.6 billion years. About his discovery, the researchers shared in the journal Astrophysical Journal Letters.
“The definition and characterization of these extremely rare stars can shed light on the early chemical evolution of our galaxy and the nature of the appearance of the first stars of the milky Way”, — the authors of the study.
For their observations, the astronomers used a spectrograph, the space telescope “Herschel”, and the Great Canary telescope, located on the island of La Palma (Spain). These tools allow to determine the presence of certain chemical elements in the stars based on the analysis of the wavelengths of their light.
Detected star is at a distance of 7500 light years from scattered field of Stardust — a halo of the milky Way, belongs to the class of dwarfs. The researchers reported that the composition of the stars detected minimal amounts of iron and calcium. At the same time, the composition contains a high concentration of carbon, which points to the antiquity of the open sun.
“Most of the chemical elements the stars J0815+4729 are light. There are carbon and calcium. The element iron, as a rule, common stars, J0815+4729 is present in a very scarce volume is of the order of a millionth fraction of the volume that is available to our Sun. It is so small that astronomers can’t even calculate it exactly. These stars all elements heavier than hydrogen and helium are found only in the case if the star is very old, one of the first in the Universe, and came under the influence of a supernova explosion that occurred somewhere around when this star was not yet formed,” — says astronomer Ian MacDonald from the University of Manchester who have not participated in the study.
Scientists say that although the star J0815+4729 is really one of the oldest in the milky Way, it has a competitor. Earlier, Australian team of astronomers has discovered a star SMSS J0313−6708, which also has the same rich in carbon and poor metal composition.
The Spanish team will continue to explore open them stars. The researchers want to obtain a clearer spectral lines of the object that will help them more accurately to classify and possibly to learn more about our galactic history.
Astronomers have found one of the oldest stars in the milky Way
Nikolai Khizhnyak