Rare isotopes in our neighboring stars present new insights into the origin of carbon and oxygen

Astronomers at Leiden University have detected uncommon isotopes of carbon and oxygen in our neighboring stars for the primary time, offering a brand new path towards higher understanding the chemical evolution of the cosmos. The outcomes are published as we speak within the journal Nature Astronomy.

The basic query in regards to the origin of carbon and oxygen in our universe has preoccupied astronomers for many years. These parts aren’t solely essential elements of the human physique however are additionally among the many most considerable parts within the universe. But within the early universe, shortly after the Big Bang, these atoms didn’t but exist.

Almost every part we see round us is constructed from atoms that have been solid within the sizzling facilities of stars. From probably the most primary atoms, hydrogen and helium, huge stars produce heavier parts comparable to carbon, nitrogen and oxygen.

“Nuclear fusion in stars is a complex process and is just the starting point of chemical evolution,” says Darío González Picos (Leiden University), who headed the analysis. When a star reaches the top of its life, this newly solid materials is dispersed out into area, both by gently shedding its outer layers or a dramatic supernova explosion.

This cosmic recycling enriches the gasoline in our Milky Way, offering the uncooked materials from which new stars and planets like Earth will kind. Each star’s gentle due to this fact carries a chemical fingerprint of this historical past.

The group of González Picos, Ignas Snellen, and Sam de Regt have discovered a brand new solution to learn these chemical fingerprints by learning isotopes—completely different kinds of a component. While the variety of protons units the chemical properties of a component (e.g., six for carbon), the variety of neutrons can fluctuate. On Earth, 99% of carbon atoms have six neutrons, however a small fraction has seven. The group has now efficiently measured these isotope ratios for each carbon and oxygen in 32 neighboring stars with unprecedented precision.

“We now see that stars that are less chemically enriched than the sun have fewer of these minor isotopes,” says co-author de Regt (Leiden University). “This finding confirms what some models of galactic chemical evolution have predicted and now provides a new tool to rewind the chemical clock of the cosmos.”

What is outstanding about this examine is that each one the information used comes from the archives of a telescope on the island of Hawaii, the Canada France Hawaii Telescope (CHFT). “The observations were originally made for a completely different reason than the one we are using them for now,” says co-author Snellen (Leiden University). “It was entirely Darío’s idea to use the high-resolution spectra, which were actually intended for the discovery of planets, for this isotope research—with impressive results.”

González Picos concludes, “This cosmic detective story is ultimately about our own origins, helping us to understand our place in the long chain of astrophysical events, and why our world looks the way it does.”