Simulation helps study oldest-known star in galaxy

Astrophysicists conducted a simulation study in order to have a better understanding of the formation of the oldest-known star in the galaxy.

Research led by Dr. Stefano Bovino at the Institute for Astrophysics Gottingen (IAG), investigated SMSS J031300.36-670839.3, on a supercomputer of the North-German Supercomputing Alliance and by using the star's abundance patterns, the scientists have performed cosmological simulations which included the dynamics of gas and dark matter as well as the chemical evolution.

From this simulation, the scientists expected to obtain an improved understanding of the transition from the first to the second generation of stars in the universe. The stars of the first generation have formed out of a primordial gas consisting only of hydrogen and helium. Their mass was ranging from ten to five hundred times the mass of the Sun.

Nuclear processes in the interior of these stars have created heavy elements like iron, silicon, carbon and oxygen. When these stars died during the first supernova explosions, the heavy elements have been ejected, and stars of the second generation could form.

Dr. Bovino said that even for the oldest-known star in the Milky Way galaxy, their simulations indicated that the gas efficiently cools due to the presence of heavy elements and such conditions favor the formation of low-mass stars.

Prof. Dominik Schleicher at the IAG, said that it seems very likely that this star was indeed one of the very first stars forming out of the metal-enriched gas, providing the chemical conditions right after the first supernova explosion.

The study is published in the Astrophysical Journal Letters.