2024AJ....167..184R


Query : 2024AJ....167..184R

2024AJ....167..184R - Astron. J., 167, 184 (2024/April-0)

High-resolution Spectroscopic Analysis of Four Unevolved Barium Stars.

RORIZ M.P., HOLANDA N., DA CONCEICAO L.V., JUNQUEIRA S., DRAKE N.A., SONALLY A. and PEREIRA C.B.

Abstract (from CDS):

A classical local thermodynamic equilibrium analysis, based on high-resolution spectroscopic data, is performed for a sample of three potential barium dwarf candidates and one star already recognized as such. We derived their atmospheric parameters, estimated their masses and luminosities, and determined chemical abundances for a set of 21 elements, including CNO. Some elemental abundances are derived for the first time in HD 15096, HD 37792, and HD 141804. The program stars are dwarfs/subgiants with metallicities typical of disk stars, exhibiting moderate carbon enhancements, with [C/Fe] ratios ranging from +0.29 to +0.66 dex, and high levels of slow neutron-capture (s-process) elements, with [s/Fe] ≳ + 1.0 dex. As spectroscopic binaries, their peculiarities are attributable to mass transfer events. The observed neutron-capture patterns of were individually compared with two sets of s-process nucleosynthesis models (Monash and FRUITY), yielding dilution factors and masses estimates for the former polluting asymptotic giant branch stars. Low-mass (≲3.0 M⊙) models successfully reproduce the observations. In addition, we estimated mean neutron exposures on the order of 0.6-0.7 mb–1 for the s-processed material observed in their envelopes. Applying an empirical initial-final mass relation, we constraint in ∼0.7 M⊙ the mass of their dim white dwarf companions. Moreover, our kinematic study revealed that the program stars are members of the thin disk, with probabilities greater than 70%. Hence, we identified HD 15096 and HD 37792 as new barium dwarfs and confirmed that HD 141804 is a barium dwarf. Thus, the number of barium dwarfs identified in the literature from high-resolution spectroscopy increases to 71 objects.

Abstract Copyright: © 2024. The Author(s). Published by the American Astronomical Society.

Journal keyword(s): Fundamental parameters of stars - Stellar atmospheres - Stellar abundances - Chemically peculiar stars - Spectroscopy

Simbad objects: 11

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Number of rows : 11
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 HD 6434 PM* 01 04 40.1502696688 -39 29 17.584220159   8.32 7.71     G2/3V 241 1
2 HD 15096 SB* 02 26 01.7580208930 +05 46 46.348227825       7.4   G5 75 0
3 HD 37792 SB* 05 40 17.4256412712 -19 13 37.770740472   8.12 7.71     F2IV/V 58 0
4 BD+09 2384 Pe* 10 40 25.2059220888 +08 54 03.935353572   10.71 9.86     G5 22 0
5 HD 122202 SB* 14 00 18.9650138088 +04 51 25.109582904   9.85 9.36     F8 22 0
6 HD 123585 SB* 14 09 35.7949041768 -44 22 01.166065032   9.75 9.23     G0III_Ba3_CH 71 0
7 HD 141804 SB* 15 53 29.2362809376 -54 09 30.499979652   9.61 9.03     F8/G0II 23 0
8 HD 141806 ** 15 54 24.6830555592 -61 31 05.412109944   10.32 9.68     G2/3V 14 0
9 NAME Galactic Center reg 17 45 39.60213 -29 00 22.0000           ~ 16269 0
10 CD-62 1346 Pe* 21 06 02.9219229360 -61 33 44.645403600   10.55 9.85 9.56 9.027 CEMP-s 70 0
11 HD 207585 SB* 21 50 34.7136512016 -24 11 11.686804584   10.50 9.78     G2II:Ba1.5CH1Fe-1 55 0

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