July 24, 2021

The Astrophysics Institute of the Canary Islands discovers one of the oldest stars of the Milky Way – The Province

The Astrophysics Institute of the Canary Islands discovers one of the oldest stars of the Milky Way - The Province

An international team of researchers, in which the doctors of the Institute of Astrophysics of the Canary Islands (IAC) participate David Aguado, Jonay González Y Carlos Allende, has discovered the existence of a star very poor in metals, one of the oldest of the Milky Way and, therefore, an excellent 'messenger' of the early universe.

The star 'Pristine 221.8781 + 9.7844' It is one of the oldest of the Milky Way due to the chemical composition of its atmosphere.

Right after the 'Big Bang', the Universe was full of hydrogen, helium and a little lithium and there were still no heavier elements because these are synthesized inside the stars.

In the words of researcher David Aguado, "given that the atmosphere of the analyzed star is very poor in metals, it can be said that it is one of the oldest objects of the Milky Way and, of course, before the birth of the Sun."

In that line, he adds that this star will help "better understand" certain aspects of the origin of the Milky Way and how the first stars were formed.

In order to reach these conclusions, detailed follow-up studies have been carried out with the ISIS instrument, in the William Herschel Telescope, and with the IDS instrument, in the Isaac Newton Telescope, both from the Isaac Newton Group of Telescopes (ING), installed in the Roque de los Muchachos Observatory (Garafía, La Palma).

"The intermediate resolution spectroscopic images, obtained in the INT and WHT telescopes in La Palma, have allowed us to verify the low carbon content, which in this type of stars is usually very abundant," explains Carlos Allende, another of the researchers from this project.

The study of these ancient stars, such as those collected and analyzed in the Pristine project, which they lead from the Leibniz Institute of Astrophysics in Potsdam and from the University of Strasbourg, helps us to learn more about what the Universe was like in their youth, Right after the Big Bang.

Surviving stars

To carry out this recognition of surviving stars of the first stages of the Universe with pristine atmospheres, the team uses a special color filter installed in the Canada-France-Hawaii Telescope (CFHT), installed at the Manua Kea summit (Hawaii).

In this study, high-resolution spectroscopy obtained with the UVES spectrograph was also used in the VLT telescope (Paranal, ESO).

"The high resolution spectroscopic data of UVES in the VLT have allowed to measure the abundance of lithium in the atmosphere of this star, which provides additional information about the origin of the Universe", affirms Jonay González, researcher Ramón y Cajal of the IAC and collaborator in the Pristine project.


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