Detection of the Second r-process Peak Element Tellurium in Metal-Poor Stars

TL;DR

This study reports the first detection of tellurium, a second r-process peak element, in metal-poor stars, confirming its production in the main r-process component through spectroscopic observations.

Contribution

First detection of tellurium in metal-poor stars, confirming its role in the main r-process nucleosynthesis in the Galactic halo.

Findings

Tellurium detected at the second r-process peak in three stars.

Tellurium abundances align with scaled solar r-process distribution.

Supports tellurium's production in the main r-process component.

Abstract

Using near-ultraviolet spectra obtained with the Space Telescope Imaging Spectrograph onboard the Hubble Space Telescope, we detect neutral tellurium in three metal-poor stars enriched by products of r-process nucleosynthesis, BD+17 3248, HD 108317, and HD 128279. Tellurium (Te, Z=52) is found at the second r-process peak (A=130) associated with the N=82 neutron shell closure, and it has not been detected previously in Galactic halo stars. The derived tellurium abundances match the scaled solar system r-process distribution within the uncertainties, confirming the predicted second peak r-process residuals. These results suggest that tellurium is predominantly produced in the main component of the r-process, along with the rare earth elements.