July 25, 2021

A "prehistoric" star

A "prehistoric" star

An international team of astronomers in which the Institute of Astrophysics of the Canary Islands (IAC) participates has discovered a very poor star in metals, which means that it is one of the oldest known in the Milky Way and, therefore, an unparalleled witness of how the first moments of the universe were.

The new object has received the name of Pristine 221.8781 + 9.7844, and is much earlier than the formation of the Sun. The chemical composition of its atmosphere, very poor in metals, has revealed that it is one of the oldest of those existing in our galaxy .

«Right after the Big Bang, the Universe was full of hydrogen, helium and a little lithium. There were still no heavier elements because they are synthesized inside the stars. This star is going to help us better understand certain aspects of the origin of the Milky Way and how the first stars were formed ", says David Aguado, one of the IAC scientists who has participated in the research.

Scientists have studied the star through the ISIS instrument, in the William Herschel Telescope, and with the IDS instrument, in the Isaac Newton Telescope, both of 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 to learn more about what the Universe was like in their youth, Right after the Big Bang. 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 in the Mauna Kea summit (Hawaii), explains the Institute of Astrophysics of the Canary Islands in a statement.


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