English
Related papers

Related papers: What we do and do not know about the s-process

200 papers

In the past years the observational evidence that s-process elements from Sr to Pb are produced by stars ascending the socalled Asymptotic Giant Branch (or AGB) could not be explained by self-consistent models, forcing researchers to…

Solar and Stellar Astrophysics · Physics 2017-11-09 S. Palmerini , O. Trippella , M. Busso , D. Vescovi , M. Petrelli , A. Zucchini , F. Frondini

Barium stars show enhanced abundances of the slow neutron capture (s-process) heavy elements, and for this reason they are suitable objects for the study of s-process elements. The aim of this work is to quantify the contributions of the…

Astrophysics · Physics 2009-11-11 Dinah M. Allen , Beatriz Barbuy

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

A major source of uncertainty in AGB models is the partial-mixing process of hydrogen, required for the formation of the so-called $^{13}$C pocket. Among the attempts to derive a self-consistent treatment of this physical process, there are…

Solar and Stellar Astrophysics · Physics 2020-10-27 Diego Vescovi , Sergio Cristallo

Context. Barium (Ba) stars are dwarf and giant stars enriched in elements heavier than iron produced by the slow neutron-capture process (s process). They belong to binary systems where the primary star evolved through the asymptotic giant…

Solar and Stellar Astrophysics · Physics 2018-12-12 B. Cseh , M. Lugaro , V. D'Orazi , D. B. de Castro , C. B. Pereira , A. I. Karakas , L. Molnár , E. Plachy , R. Szabó , M. Pignatari , S. Cristallo

During the evolution on the AGB, S-type stars are the first objects to experience s-process nucleosynthesis and third dredge-ups, and therefore to exhibit sprocess signatures in their atmospheres. Their significant mass loss rates (10^-7 to…

Solar and Stellar Astrophysics · Physics 2010-11-10 Pieter Neyskens , Sophie Van Eck , Bertrand Plez , Stéphane Goriely , Lionel Siess , Alain Jorissen

Oxygen and carbon-rich AGB stars - and objects directly polluted by them - are excellent laboratories to investigate the nucleosynthesis and mixing processes occurring during the later phases of the of low- and intermediate-mass star…

Solar and Stellar Astrophysics · Physics 2026-04-13 Sophie Van Eck , Carlos Abia , Inma Dominguez

We present a new measurement of the $\alpha$-spectroscopic factor ($S_\alpha$) and the asymptotic normalization coefficient (ANC) for the 6.356 MeV 1/2$^+$ subthreshold state of $^{17}$O through the $^{13}$C($^{11}$B, $^{7}$Li)$^{17}$O…

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

Neutron captures produce the vast majority of abundances of elements heavier than iron in the Universe. Beyond the classical slow (s) and rapid (r) processes, there is observational evidence for neutron-capture processes that operate at…

Solar and Stellar Astrophysics · Physics 2025-11-11 Maria Lugaro , Marco Pignatari , René Reifarth , Michael Wischer

Results from observations report a growing number of metal-poor stars showing an abundance pattern midway between the s- and r-processes. These so-called r/s-stars raise the need for an intermediate neutron capture process (i-process),…

Solar and Stellar Astrophysics · Physics 2022-06-29 A. Choplin , L. Siess , S. Goriely

The $s$-process in massive stars produces the weak component of the $s$-process (nuclei up to $A \sim 90$), in amounts that match solar abundances. For heavier isotopes, such as barium, production through neutron capture is significantly…

Solar and Stellar Astrophysics · Physics 2017-05-26 Nobuya Nishimura , Raphael Hirschi , Thomas Rauscher , Alexander St. J. Murphy , Gabriele Cescutti

Low mass Asymptotic Giant Branch stars are among the most important polluters of the interstellar medium. In their interiors, the main component (A>90) of the slow neutron capture process (the s-process) is synthesized, the most important…

Solar and Stellar Astrophysics · Physics 2018-06-13 S. Cristallo , M. La Cognata , C. Massimi , A. Best , S. Palmerini , O. Straniero , O. Trippella , M. Busso , G. F. Ciani , F. Mingrone , L. Piersanti , D. Vescovi

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

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

Barium stars are one of the important probes to understand the origin and evolution of slow neutron-capture process elements in the Galaxy. These are extrinsic stars, where the observed s-process element abundances are believed to have an…

Solar and Stellar Astrophysics · Physics 2020-10-15 J. Shejeelammal , Aruna Goswami , Partha Pratim Goswami , Rajeev Singh Rathour , Thomas Masseron

We compare updated Torino postprocessing asymptotic giant branch (AGB) nucleosynthesis model calculations with isotopic compositions of mainstream SiC dust grains from low-mass AGB stars. Based on the data-model comparison, we provide new…

Solar and Stellar Astrophysics · Physics 2018-10-10 Nan Liu , Roberto Gallino , Sergio Cristallo , Sara Bisterzo , Andrew M. Davis , Reto Trappitsch , Larry R. Nittler

We study the s-process abundances (A > 90) at the epoch of the solar-system formation. AGB yields are computed with an updated neutron capture network and updated initial solar abundances. We confirm our previous results obtained with a…

Solar and Stellar Astrophysics · Physics 2015-06-19 S. Bisterzo , C. Travaglio , R. Gallino , M. Wiescher , F. Käppeler

The s-process in massive stars, producing nuclei up to $A\approx 90$, has a different behaviour at low metallicity if stellar rotation is significant. This enhanced s-process is distinct from the s-process in massive stars around solar…

Solar and Stellar Astrophysics · Physics 2018-02-19 N. Nishimura , R. Hirschi , T. Rauscher

A clear definition of the contribution from the slow neutron-capture process (s process) to the solar abundances between Fe and the Sr-Zr region is a crucial challenge for nuclear astrophysics. Robust s-process predictions are necessary to…

Solar and Stellar Astrophysics · Physics 2025-10-22 Marco Pignatari , Roberto Gallino , Rene Reifarth