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