Neutron-capture elements in the very metal-poor star HD88609: another st ar with excesses of light neutron-capture elements

TL;DR

This study analyzes the neutron-capture element abundances in the metal-poor star HD88609, revealing a unique pattern of light element excesses and providing insights into early Galactic nucleosynthesis processes.

Contribution

It presents the first detailed abundance pattern of 19 neutron-capture elements in HD88609, highlighting a distinct trend of light element excesses compared to heavy elements.

Findings

HD88609 shows large excesses of light neutron-capture elements.

The abundance pattern decreases from Sr to Yb, differing from r-process enhanced stars.

The pattern is similar to that of HD122563, suggesting a common nucleosynthesis origin.

Abstract

We obtained a high resolution, high signal-to-noise UV-blue spectrum of the extremely metal-poor red giant HD88609 to determine the abundances of heavy elements. Nineteen neutron-capture elements are detected in the spectrum. Our analysis revealed that this object has large excesses of light neutron-capture elements while heavy neutron-capture elements are deficient. The abundance pattern shows a continuously decreasing trend, as a function of atomic number, from Sr to Yb, which is quite different from those in stars with excesses of r-process elements. Such an abundance pattern is very similar to that of HD122563 that was studied by our previous work. The results indicate that the abundance pattern found in the two stars could represent the pattern produced by the nucleosynthesis process that provided light neutron-capture elements in the very early Galaxy.