# RAVE J203843.2-002333: The first highly r-process-enhanced star identified in the RAVE survey

## TL;DR

This paper reports the discovery and detailed chemical analysis of RAVE J203843.2-002333, the first highly r-process-enhanced star identified in the RAVE survey, providing insights into early nucleosynthesis and stellar evolution.

## Contribution

It presents the first identification of a highly r-process-enhanced star within the RAVE survey and provides detailed elemental abundances, including uranium and thorium, for this rare object.

## Key findings

- Star is very metal-poor with [Fe/H] = -2.91.
- Star shows strong r-process enhancement with [Eu/Fe] = +1.64.
- Age estimated at approximately 13 billion years.

## Abstract

We report the discovery of RAVE J203843.2-002333, a bright (V = 12.73), very metal-poor ([Fe/H] = -2.91), r-process-enhanced ([Eu/Fe] = +1.64 and [Ba/Eu] = -0.81) star selected from the RAVE survey. This star was identified as a metal-poor candidate based on its medium-resolution (R ~ 1,600) spectrum obtained with the KPNO/Mayall Telescope, and followed-up with high-resolution (R ~ 66,000) spectroscopy with the Magellan/Clay Telescope, allowing for the determination of elemental abundances for 24 neutron-capture elements, including thorium and uranium. RAVE J2038-0023 is only the fourth metal-poor star with a clearly measured U abundance. The derived chemical-abundance pattern exhibits good agreement with those of other known highly r-process-enhanced stars, and evidence in hand suggests that it is not an actinide-boost star. Age estimates were calculated using Th/X and U/X abundance ratios, yielding a mean age of 13.0 +/- 1.1 Gyr.