The first stars of the Milky Way
Researchers from the Institute of Astrophysics of Canada found a star, the key to the process of forming the first chemical elements in the galaxy. They managed to identify one of the stars with the smallest amount of metal. The object is distant from the Sun at 7500 light years and is located in the halo of the Milky Way. The star is still at the stage of the main sequence, by mass 0.7 times the solar one, and the surface temperature is 400 degrees higher.
This detection was performed using spectra acquired by OSIRIS. Spectroscopy allows you to decompose the light of celestial bodies to study their physical and chemical characteristics. The analysis showed that J0815 + 4729 has only one millionth of calcium and iron, which the Sun can hold. But there is also a high level of carbon - 15% of the sun. Researchers know only a few similar stars living in the halo, where the most ancient and metal-poor objects are located. The theory says that these stars could use material from the first supernovae, whose progenitors were massive objects and appeared 300 million years after the Big Bang.
In fact, the star flashed back in the data of the Sloan digital celestial survey, and later it was observed with a Herschel telescope. In the future, scientists plan to use a HORS spectrograph with high resolution and analyze the chemical composition of such objects.