Results 1 to 10 of about 3,760 (219)

Rubidium-Rich Asymptotic Giant Branch Stars [PDF]

open access: yesScience, 2006
A long-debated issue concerning the nucleosynthesis of neutron-rich elements in asymptotic giant branch (AGB) stars is the identification of the neutron source. We report intermediate-mass (4 to 8 solar masses) AGB stars in our Galaxy that are rubidium-rich as a result of overproduction of the long-lived radioactive isotope 87
D A García-Hernández   +2 more
exaly   +5 more sources

FLUORINE ABUNDANCES IN GALACTIC ASYMPTOTIC GIANT BRANCH STARS

open access: yesAstrophysical Journal Letters, 2010
An analysis of the fluorine abundance in Galactic asymptotic giant branch (AGB) carbon stars (24 N-type, 5 SC-type, and 5 J-type) is presented. This study uses the state-of-the-art carbon-rich atmosphere models and improved atomic and molecular line lists in the 2.3 μm region.
K Cunha, S Cristallo, G Imbriani
exaly   +7 more sources

Asymptotic Giant Branch Stars and presolar grains [PDF]

open access: yesEPJ Web of Conferences, 2020
Starting from the recognition that radioactive isotopes were present alive in the Early Solar System, inducing composition anomalies from their decay, and through the discovery that other important anomalies affected also stable species, we shall discuss
Busso Maurizio   +2 more
doaj   +3 more sources

Evolution of Asymptotic Giant Branch Stars [PDF]

open access: yesAnnual Review of Astronomy and Astrophysics, 2005
▪ Abstract  The current status of modeling the evolution and nucleosynthesis of asymptotic giant branch (AGB) stars is reviewed. The principles of AGB evolution have been investigated in recent years leading to improved and refined models, for example with regard to hot-bottom burning or the third dredge-up.
Falk Herwig
exaly   +2 more sources

Post-AGB Stars as Tracers of AGB Nucleosynthesis: An Update

open access: yesUniverse, 2022
The chemical evolution of galaxies is governed by the chemical yields from stars, and here we focus on the important contributions from asymptotic giant branch (AGB) stars. AGB nucleosynthesis is, however, still riddled with complexities.
Devika Kamath, Hans Van Winckel
doaj   +1 more source

Extremely Metal-Poor Asymptotic Giant Branch Stars

open access: yesUniverse, 2022
Little is known about the first stars, but hints on this stellar population can be derived from the peculiar chemical composition of the most metal-poor objects in the Milky Way and in resolved stellar populations of nearby galaxies.
Mario Cirillo   +2 more
doaj   +1 more source

The Missing Lead: Developments in the Lead (Pb) Discrepancy in Intrinsically s-Process Enriched Single Post-AGB Stars

open access: yesUniverse, 2021
Lead (Pb) is predicted to have large over-abundances with respect to other s-process elements in Asymptotic Giant Branch (AGB) stars, especially of low metallicities.
Devika Kamath, Hans Van Winckel
doaj   +1 more source

Vortices in the Wakes of Asymptotic Giant Branch Stars [PDF]

open access: yesThe Astrophysical Journal, 2007
Vortices have been postulated at a range of size scales in the universe, including at the stellar-size scale. While hydrodynamically simulating the wind from an asymptotic giant branch (AGB) star moving through and sweeping up its surrounding interstellar medium (ISM), we have found vortices on the size scale of 10-1 to 101 pc in the wake of the star ...
Wareing, C. J.   +2 more
openaire   +2 more sources

Turbulent dynamo in asymptotic giant branch stars [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society, 2002
Using recent results on the operation of turbulent dynamos, we show that a turbulent dynamo can amplify a large scale magnetic field in the envelopes of asymptotic giant branch (AGB) stars. We propose that a slow rotation of the AGB envelope can fix the symmetry axis, leading to the formation of an axisymmetric magnetic field structure.
Soker, Noam, Zoabi, Essam
openaire   +2 more sources

Luminosity Functions for Asymptotic Giant Branch Stars [PDF]

open access: yesSymposium - International Astronomical Union, 1984
To understand the evolution of carbon and oxygen rich asymptotic giant branch (AGB) stars it is important to observationally establish the relations between parameters such as luminosity, age, and metallicity. The existence of luminous (brighter than the top of the first giant branch) AGB stars in clusters in the Magellanic Clouds (Mould and Aaronson ...
Jay A. Frogel, V.M. Blanco
openaire   +1 more source

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