2025ApJ...984..176X


Query : 2025ApJ...984..176X

2025ApJ...984..176X - Astrophys. J., 984, 176 (2025/May-2)

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

XIE X.-J., SHI J., YAN H.-L., CHEN T.-Y., ALLENDE PRIETO C., BEERS T.C., JIN S.-L., LIU S., LI C.-Q., ZHOU Z.-M., DING M.-Y. and TANG Y.-J.

Abstract (from CDS):

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.

Abstract Copyright: © 2025. The Author(s). Published by the American Astronomical Society.

Journal keyword(s): R-process - Nucleosynthesis - Stellar abundances - Milky Way disk

Simbad objects: 5

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Number of rows : 5
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026
#notes
1 LAMOST J020632.21+494127.9 * 02 06 32.1877413151 +49 41 27.978053694           ~ 5 0
2 UCAC4 548-006160 * 03 14 48.6595051778 +19 27 47.639607761   13.732 12.236 11.860   ~ 1 0
3 UCAC4 583-041046 * 07 55 48.2293582633 +26 27 56.277257463   13.530 12.883 12.765   ~ 1 0
4 GrW 170817 GWE 13 09 48.0850 -23 22 53.343           ~ 2683 0
5 HD 222925 Pe* 23 45 17.6074777008 -61 54 42.835286016   9.56 9.03     ApSrEu 83 0

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