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We demonstrate that a massive asymptotic giant branch (AGB) star is a good candidate as the main source of short-lived radionuclides in the early solar system. Recent identification of massive (4-8 solar masses) AGB stars in the Galaxy,…

We present new theoretical stellar yields and surface abundances for three grids of metal-rich asymptotic giant branch (AGB) models. Post-processing nucleosynthesis results are presented for stellar models with initial masses between…

Solar and Stellar Astrophysics · Physics 2016-07-06 Amanda I. Karakas , Maria Lugaro

Meteoritic studies of solar system objects show evidence of nucleosynthetic heterogeneities that are inherited from small presolar grains (< 10 $\mu$m) formed in stellar environments external to our own. The initial distribution and…

Earth and Planetary Astrophysics · Physics 2022-03-17 Mark A. Hutchison , Jean-David Bodénan , Lucio Mayer , Maria Schönbächler

[Abridged] Barium stars are moderately rare, chemically peculiar objects, which are believed to be the result of the pollution of an otherwise normal star by material from an evolved companion on the asymptotic giant branch (AGB). We aim to…

Solar and Stellar Astrophysics · Physics 2015-05-28 Alan Alves-Brito , Amanda Karakas , David Yong , Jorge Meléndez , Sergio Vásquez

Extreme excesses of $^{13}C$ ($^{12}C$/$^{13}C$<10) and $^{15}N$ ($^{14}N$/$^{15}N$<20) in rare presolar SiC grains have been considered diagnostic of an origin in classical novae, though an origin in core collapse supernovae (CCSNe) has…

Solar and Stellar Astrophysics · Physics 2016-04-13 Nan Liu , Larry R. Nittler , Conel M. O'D. Alexander , Jianhua Wang , Marco Pignatari , Jordi Jose , Ann Nguyen

We explore the possibility that the short-lived radionuclides $^{26}$Al, $^{60}$Fe, $^{107}$Pd, and $^{182}$Hf inferred to be present in the proto-solar cloud originated from $3-8 M_{\odot}$ Asymptotic Giant Branch (AGB) stars. Models of…

Solar and Stellar Astrophysics · Physics 2017-02-22 G. J. Wasserburg , Amanda I. Karakas , Maria Lugaro

The s-enhanced and very metal-poor star CS 30322-023 shows a puzzling abundance pattern of the neutron-capture elements, i.e. several neutron-capture elements such as Ba, Pb etc. show enhancement, but other neutron-capture elements such as…

Astrophysics · Physics 2010-11-05 W. Y. Cui , B. Zhang , K. Ma , L. Zhang

We observed the AGB stars S Ori, GX Mon and R Cnc with the MIDI instrument at the VLTI. We compared the data to radiative transfer models of the dust shells, where the central stellar intensity profiles were described by dust-free dynamic…

Solar and Stellar Astrophysics · Physics 2015-06-17 I. Karovicova , M. Wittkowski , K. Ohnaka , D. A. Boboltz , E. Fossat , M. Scholz

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 a new model of interstellar dust in which large grains are a single composite material, ``astrodust,'' and nanoparticle-sized grains come in distinct varieties including polycyclic aromatic hydrocarbons (PAHs). We argue that a…

Astrophysics of Galaxies · Physics 2023-06-07 Brandon S. Hensley , B. T. Draine

The outflows of oxygen-rich asymptotic giant branch (AGB) stars are thought to be driven by radiation pressure by photon scattering on grains with sizes of tenths of microns. The details of the formation of dust in the extended atmospheres…

Solar and Stellar Astrophysics · Physics 2018-12-05 T. Khouri , W. H. T. Vlemmings , H. Olofsson , C. Ginski , E. De Beck , M. Maercker , S. Ramstedt

Laboratory analyses on fine-grained diamond residues from primitive meteorites have shown that nano-diamonds represent the most abundant form of presolar dust preserved in meteoritic samples. The presolar diamonds carry isotopic anomalies…

Astrophysics · Physics 2007-05-23 A. C. Andersen , U. G. Jorgensen , F. M. Nicolaisen , P. G. Sorensen , K. Glejbol

Weak G-band (wGb) stars are very peculiar red giants almost devoided of carbon and often mildly enriched in lithium. Despite their very puzzling abundance patterns, very few detailed spectroscopic studies existed up to a few years ago,…

Solar and Stellar Astrophysics · Physics 2016-02-17 A. Palacios , G. Jasniewicz , T. Masseron , F. Thévenin , J. Itam-Pasquet , M. Parthasarathy

We discuss theoretical AGB predictions for hydrogen-deficient PG 1159 stars and Sakurai's object, which show peculiar enhancements in He, C and O, and how these enhancements may be understood in the framework of a very late thermal pulse…

Solar and Stellar Astrophysics · Physics 2011-07-05 R. Gallino , O. Straniero , E. Zinner , M. Jadhav , L. Piersanti , S. Cristallo , S. Bisterzo

Refractory inclusions in chondritic meteorites, namely amoeboid olivine aggregates (AOAs) and Ca-Al-rich inclusions (CAIs), are among the first solids to have formed in the solar system. The isotopic composition of CAIs is distinct from…

Earth and Planetary Astrophysics · Physics 2024-01-15 Christian A. Jansen , Christoph Burkhardt , Yves Marrocchi , Jonas M. Schneider , Elias Wölfer , Thorsten Kleine

Post-asymptotic giant branch (post-AGB) stars are known to be chemically diverse. In this paper we present the first observational evidence of a star that has failed the third dredge-up (TDU). J005252.87-722842.9 is a A-type ($T_{\rm eff}$…

Solar and Stellar Astrophysics · Physics 2017-10-13 D. Kamath , H. Van Winckel , P. R. Wood , M. Asplund , M. , A. I. Karakas , J. C. Lattanzio

Unravelling the composition and characteristics of gas and dust lost by asymptotic giant branch (AGB) stars is important as these stars play a vital role in the chemical life cycle of galaxies. The general hypothesis of their mass loss…

Solar and Stellar Astrophysics · Physics 2019-08-27 Jels Boulangier , David Gobrecht , Leen Decin , Alex de Koter , Jeremy Yates

AGB stars are responsible for producing a variety of elements, including carbon, nitrogen, and the heavy elements produced in the slow neutron-capture process ($s$-elements). There are many uncertainties involved in modelling the evolution…

Solar and Stellar Astrophysics · Physics 2015-04-22 C. Abate , O. R. Pols , A. I. Karakas , R. G. Izzard

Describing the comprehensive evolutionary scenario for asteroids is key to explaining the various physical processes of the solar system. Bulk-scale carbonaceous chondrites (CCs) possibly record the primordial information associated with…

Earth and Planetary Astrophysics · Physics 2021-02-24 Ryota Fukai , Sota Arakawa

This work presents a large consistent study of molybdenum (Mo) and ruthenium (Ru) abundances in the Milky Way. These two elements are important nucleosynthetic diagnostics. In our sample of 71 Galactic metal-poor field stars, we detect Ru…

Solar and Stellar Astrophysics · Physics 2014-09-05 Camilla J. Hansen , Anja C. Andersen , Norbert Christlieb
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