The first stars are not born alone

The first stars in the universe were not usually alone, but formed clusters and clusters. This is the conclusion of Tilman Hartwig (University of Tokyo) and colleagues in a recently published article Astrophysical JournalAfter comparing notes with computer accounts.

No one has ever seen a true first-generation star. These massive stars (for historical reasons they are also called The third populationStars) emerged from primordial clouds of hydrogen and helium shortly after the Big Bang, and lived only a few million years before ending their existence in a supernova explosion. Little is known about the conditions of their formation, or about their masses–information crucial to understanding the formation and early evolution of the first galaxies.

To learn more about the first generation of stars, Hartwig and his Japanese colleagues studied the formation of the second generation. These so-called group II stars are born from interstellar clouds already slightly enriched with heavier elements produced in the cores of group III stars and blasted into space by the explosions of these earlier stars.

Thanks to detailed calculations of the nuclear fusion processes that occur in stars, astronomers know what combination of elements should produce III supernovae of different masses. By comparing the output of these supernovae with the observed amounts of heavy elements in the Population II star, astronomers can determine whether this next-generation star formed from material enriched by a single supernova or multiple explosions in the same region.

The research team has collected archival data on the formation of 462 supernovae (also known as supernovae) stars in our Milky Way galaxy. Together with their theoretical results on the number of supernovae, they fed this data into a neural network.machine learningThe result: only a third of stars appear to have formed from material enriched by just one supernova.

According to the authors, this means that most of the extremely poor stars are likely to be poly-enriched, indicating that the first stars formed in small clusters. Perhaps this is not really surprising: the same is true for most of the massive stars born today. (GS/E)

The first stars are not born alone