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Related papers: Learning about the intermediate neutron-capture pr…

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About half of the mass of all heavy elements with mass number A > 90 is formed through the slow neutron capture process (s-process), occurring in evolved asymptotic giant branch (AGB) stars with masses ~1-6 $\rm{M_{\odot}}$. The s-process…

Solar and Stellar Astrophysics · Physics 2025-09-03 A. J. Dimoff , R. J. Stancliffe , C. J. Hansen , R. M. Seeburger , H. Taylor

A recent survey of a large sample of Galactic intermediate-mass (>3 Msun) asymptotic giant branch (AGB) stars shows that they exhibit large overabundances of rubidium (Rb) up to 100--1000 times solar. These observations set constraints on…

Solar and Stellar Astrophysics · Physics 2015-06-04 Mark A. van Raai , M. Lugaro , Amanda I. Karakas , Domingo A. Garcia-Hernandez , David Yong

Context: This paper is part of a larger project in which we study the chemical abundances of extra-galactic post-AGB stars with the ultimate goal of improving our knowledge of the poorly understood AGB third dredge-up mixing processes and…

Solar and Stellar Astrophysics · Physics 2015-11-04 K. De Smedt , H. Van Winckel , D. Kamath , P. R. Wood

Barium (Ba) stars help to verify asymptotic giant branch (AGB) star nucleosynthesis models since they experienced pollution from an AGB binary companion and thus their spectra carry the signatures of the slow neutron capture process (s…

Solar and Stellar Astrophysics · Physics 2024-08-21 B. Világos , B. Cseh , A. Yagüe López , M. Joyce , A. Karakas , G. Tagliente , M. Lugaro

We present the abundance analyses of 7 Carbon enhanced metal-poor (CEMP) stars to understand the origin of carbon in them. We used high-resolution optical spectra to derive abundances of various elements. We also used low-resolution…

Solar and Stellar Astrophysics · Physics 2021-07-14 A. Susmitha , D. K. Ojha , T. Sivarani , J. P. Ninan , A. Bandyopadhyay , Arun Surya , Athira Unni

Recent observations of r-process-enriched metal-poor star abundances reveal a non-uniform abundance pattern for elements $Z\leq47$. Based on non-correlation trends between elemental abundances as a function of Eu-richness in a large sample…

Within the framework of the current models for the slow neutron capture (s) process in Asymptotic Giant Branch (AGB) stars we explore the uncertainties introduced by the assumptions made on stellar modeling. On the basis of star models…

Astrophysics · Physics 2009-10-31 Maria Lugaro , Falk Herwig

CEMP-s stars are very metal-poor stars with enhanced abundances of carbon and s-process elements. They form a significant proportion of the very metal-poor stars in the Galactic halo and are mostly observed in binary systems. This suggests…

Solar and Stellar Astrophysics · Physics 2014-03-05 Carlo Abate , Onno R. Pols , Robert G. Izzard , Amanda I. Karakas

Contrary to previous expectations, recent evolutionary models of zero-metallicity stars show that the development of mixing episodes at the beginning of the AGB phase allows low- and intermediate-mass stars to experience thermal pulses. If…

Astrophysics · Physics 2009-11-07 Stephane Goriely , Lionel Siess

We present the first detailed and homogeneous analysis of the s-element content in Galactic carbon stars of N-type. Abundances of Sr,Y, Zr (low-mass s-elements, or ls) and of Ba, La, Nd, Sm and Ce (high-mass s-elements, hs) are derived…

Astrophysics · Physics 2009-11-07 C. Abia , I. Dominguez , R. Gallino , M. Busso , S. Masera , O. Straniero , P. de Laverny , B. Plez , J. Isern

Nucleosynthesis in the s process takes place in the He burning layers of low mass AGB stars and during the He and C burning phases of massive stars. The s process contributes about half of the element abundances between Cu and Bi in solar…

Solar and Stellar Astrophysics · Physics 2015-05-20 Franz Käppeler , Roberto Gallino , Sara Bisterzo , Wako Aoki

Asymptotic Giant Branch (AGB) stars play a fundamental role in the s-process nucleosynthesis during their thermal pulsing phase. The theoretical predictions obtained by AGB models at different masses, s-process efficiencies, dilution…

Solar and Stellar Astrophysics · Physics 2014-11-20 S. Bisterzo , R. Gallino , O. Straniero , W. Aoki

It has been shown that proton ingestion episodes can happen in the formation of hot-subdwarf stars, and that neutron-capture processes are possible in those cases. Moreover, some helium-rich hot subdwarfs display extraordinarily high…

Solar and Stellar Astrophysics · Physics 2025-07-16 T. Battich , M. M. Miller Bertolami , A. Weiss , M. Dorsch , A. M. Serenelli , S. Justham

In past decades a lot of progress has been made towards understanding the main s-process component that takes place in thermally pulsing Asymptotic Giant Branch (AGB) stars. During this process about half of the heavy elements, mainly…

Instrumentation and Methods for Astrophysics · Physics 2015-05-14 M. Heil , A. Juseviciute , F. Kaeppeler , R. Gallino , M. Pignatari , E. Uberseder

Employing spectra obtained with the new Keck I HIRES near-UV sensitive detector, we have performed a comprehensive chemical composition analysis of the binary blue metal-poor star CS29497-030. Abundances for 29 elements and upper limits for…

Stellar photospheres of post-asymptotic giant branch stars bear witness to the internal chemical enrichment processes, integrated over their entire stellar evolution. Here we study post-AGB stars in the Large Magellanic Cloud (LMC). With…

Solar and Stellar Astrophysics · Physics 2015-06-15 Els van Aarle , Hans Van Winckel , Kenneth De Smedt , Devika Kamath , Peter R. Wood

The standard model for the operation of the s-process in asymptotic giant branch (AGB) stars predicts that low-metallicity ([Fe/H] <= -1) AGB stars should exhibit large overabundances of Pb and Bi as compared to other s-elements. Eight CH…

Astrophysics · Physics 2011-05-23 S. Van Eck , S. Goriely , A. Jorissen , B. Plez

Asymptotic giant branch (AGB) stars can experience proton ingestion events (PIEs), leading to a rich nucleosynthesis. During a PIE, the intermediate neutron capture process (i-process) develops, leading to the production of trans-iron…

Solar and Stellar Astrophysics · Physics 2024-10-17 A. Choplin , L. Siess , S. Goriely , S. Martinet

The heavy elements formed by neutron capture processes have an interesting history from which we can extract useful clues to and constraints upon both the characteristics of the processes themselves and the star formation and…

Astrophysics · Physics 2009-11-07 J. W. Truran , J. J. Cowan , C. A. Pilachowski , C. Sneden

We present post process neutron capture computations for Asymptotic Giant Branch stars of 1.5 to 3 Mo and metallicities -1.3 to 0.1. The reference stellar models are computed with the FRANEC code, using the Schwarzschild's criterion for…

Solar and Stellar Astrophysics · Physics 2021-02-17 Maurizio Busso , Diego Vescovi , Sara Palmerini , Sergio Cristallo , Vincenzo Antonuccio Delogu