Searching for R-process-enhanced Stars in the LAMOST Survey. II. Two New r-II Stars in the Milky Way Disk

Xie, Xiao-Jin; Shi, Jianrong; Yan, Hong-Liang; Chen, Tian-Yi; Allende Prieto, Carlos; Beers, Timothy C.; Jin, Shi-Lun; Liu, Shuai; Li, Chun-Qian; Zhou, Ze-Ming; Ding, Ming-Yi; Tang, Yao-Jia
Referencia bibliográfica

The Astrophysical Journal

Fecha de publicación:
5
2025
Número de autores
12
Número de autores del IAC
1
Número de citas
3
Número de citas referidas
2
Descripción
R-process-enhanced (RPE) stars are rare and typically metal-poor ([Fe/H] < ‑1.0), primarily found in the Milky Way halo system and dwarf galaxies. This study reports the discovery of two relatively bright, highly RPE stars ([Eu/Fe] > +0.70) located in the Milky Way disk, with [Fe/H] of ‑0.34 and ‑0.80, respectively. These two stars are selected from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope medium-resolution (R ∼ 7500) spectroscopic survey. Follow-up high-resolution (R ∼ 25,000) observations were conducted with the High Optical Resolution Spectrograph installed on the 10.4 m Gran Telescopio Canarias. We perform the determination of elemental abundances and calculate the orbital parameters. We find that they are r-II stars with elemental abundances in agreement with the solar r-process pattern. These two objects are chemically and dynamically consistent with membership in the Galactic disk and exhibit no evidence of being part of accreted systems.
Proyectos relacionados
spectrum of mercury lamp
Abundancias Químicas en Estrellas
La espectroscopía de estrellas nos permite determinar las propiedades y composiciones químicas de las mismas. A partir de esta información para estrellas de diferente edad en la Vía Láctea es posible reconstruir la evolución química de la Galaxia, así como el origen de los elementos más pesados que el boro, forjados principalmente en los interiores
Carlos
Allende Prieto