Study of the element abundances in HD 140283: the abundance robustness of the weak r- and main r-process stars

TL;DR

This study analyzes the element abundances in the metal-poor star HD 140283, identifying it as a weak r-process star with robust abundance patterns, and explores the implications for understanding the astrophysical origins of neutron-capture elements.

Contribution

It demonstrates the robustness of element abundances in weak and main r-process stars and extends the understanding of their characteristics to lighter neutron-capture elements.

Findings

HD 140283 is identified as a weak r-process star.

Element abundances in weak r-process stars are robust.

Robust abundance patterns extend to lighter neutron-capture elements in main r-process stars.

Abstract

Many works have attempted to investigate the astrophysical origin of the neutron-capture elements in the metalpoor star HD 140283. However, no definite conclusions have been drawn. In this work, using the abundancedecomposed approach, we find that the metal-poor star HD 140283 is a weak r-process star. Although this star is a weak r-process star, its Ba abundance mainly originates from the main r-process. This is the reason that the ratio [Ba/Eu]= -0.58+- 0.15 for HD 140283 is close to the ratio of the main r-process. Based on the comparison of the abundances in the six-weak r-process stars, we find that their element abundances possess a robust nature. On the other hand, we find that the robust nature of the abundance of the extreme main r-process stars ([r/Fe]>= 1.5) can be extended to the lighter neutron-capture elements. Furthermore, the abundance characteristics of the weak r-process and main r-process are investigated. The abundance robustness of the two category r-process stars could be used as the constraint of the r-process theory and could be used to investigate the astrophysical origins of the elements in the metal-poor stars and population I stars.