Meteoritic Silicon Carbide Grains with Unusual S[CLC]i[/CLC]-Isotopic Compositions: Evidence for an Origin in Low-Mass, Low-Metallicity Asymptotic Giant Branch Stars

1997 ◽  
Vol 487 (1) ◽  
pp. L101-L104 ◽  
Author(s):  
P. Hoppe ◽  
P. Annen ◽  
R. Strebel ◽  
P. Eberhardt ◽  
R. Gallino ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Isotopic Compositions ◽  
Low Metallicity ◽  
Low Mass ◽  
Giant Branch Stars

scholarly journals EVOLUTION OF THERMALLY PULSING ASYMPTOTIC GIANT BRANCH STARS. IV. CONSTRAINING MASS LOSS AND LIFETIMES OF LOW MASS, LOW METALLICITY AGB STARS

2014 ◽  
Vol 790 (1) ◽  
pp. 22 ◽  
Author(s):  
Philip Rosenfield ◽  
Paola Marigo ◽  
Léo Girardi ◽  
Julianne J. Dalcanton ◽  
Alessandro Bressan ◽  
...  
Keyword(s):  
Mass Loss ◽  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Agb Stars ◽  
Low Metallicity ◽  
Low Mass ◽  
Giant Branch Stars

scholarly journals Lithium production by thermohaline mixing in low-mass, low-metallicity asymptotic giant branch stars

2009 ◽  
Vol 5 (S268) ◽  
pp. 405-410
Author(s):  
Richard J. Stancliffe ◽  
George C. Angelou ◽  
John C. Lattanzio
Keyword(s):  
Main Sequence ◽  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Agb Stars ◽  
Low Metallicity ◽  
Low Mass ◽  
Thermal Pulses ◽  
Giant Branch Stars

AbstractWe examine the effects of thermohaline mixing on the composition of the envelopes of low-metallicity asymptotic giant branch (AGB) stars. We have evolved models of 1, 1.5 and 2M⊙ and of metallicity Z = 10−4 from the pre-main sequence to the end of the thermal pulsing asymptotic giant branch with thermohaline mixing applied throughout the simulations. We find that the small amount of 3He that remains after the first giant branch is enough to drive thermohaline mixing on the AGB and that the mixing is most efficient in the early thermal pulses, with the efficiency dropping from pulse to pulse. We note a surprising increase in the 7Li abundance, with log10ϵ(7Li) reaching values of over 2.5 in the 1.5M⊙ model. It is thus possible to get stars which are both C- and Li-rich at the same time. We compare our models to measurements of carbon and lithium in carbon-enhanced metal-poor stars which have not yet reached the giant branch. These models can simultaneously reproduced the observed C and Li abundances of carbon-enhanced metal-poor turn-off stars that are Li-rich.

scholarly journals Presolar Graphite: Noble Gases and their Origins

2003 ◽  
Vol 20 (4) ◽  
pp. 378-381 ◽  
Author(s):  
Sachiko Amari
Keyword(s):  
Noble Gases ◽  
Noble Gas ◽  
Asymptotic Giant Branch ◽  
Isotopic Ratios ◽  
Asymptotic Giant Branch Stars ◽  
Dominant Source ◽  
Low Metallicity ◽  
Low Mass ◽  
Giant Branch Stars

AbstractPresolar graphite contains a 22Ne-rich component called Ne-E(L). Noble gas studies on graphite aggregates and single grains have shown that although a dominant source of the 22Ne is 22Na, 22Ne in the He-shell of asymptotic giant branch stars have also contributed to the Ne-E(L). In addition to novae that have been considered to be a possible source of 22Na, supernovae are a likely source as well. Krypton isotopic ratios of the separates indicate that part of graphite formed in low-mass (≤3 M⊙) asymptotic giant branch stars of low metallicity (Z ≤ 0.006).

Finite Temperature Behavior of Carbon Atom Doped Silicon Clusters: Depressed Thermal Stabilities, Co-existing isomers, Reversible Dynamical Pathways and Fragmentation Channels

2021 ◽  
Author(s):  
Krati Joshi ◽  
Ashakiran Maibam ◽  
Sailaja Krishnamurty
Keyword(s):  
Silicon Carbide ◽  
Carbon Atom ◽  
Finite Temperature ◽  
Asymptotic Giant Branch ◽  
Temperature Behavior ◽  
Asymptotic Giant Branch Stars ◽  
Silicon Clusters ◽  
Thermal Stabilities ◽  
Doped Silicon ◽  
Giant Branch Stars

Silicon carbide clusters are significant due to their predominant occurrence in meteoric star dust, particularly in carbon rich asymptotic giant branch stars. Of late, they have also been recognized as...

Presolar SiC Grains of Type Y: Origin from Low‐Metallicity Asymptotic Giant Branch Stars

2001 ◽  
Vol 546 (1) ◽  
pp. 248-266 ◽  
Author(s):  
Sachiko Amari ◽  
Larry R. Nittler ◽  
Ernst Zinner ◽  
Roberto Gallino ◽  
Maria Lugaro ◽  
...  
Keyword(s):  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Low Metallicity ◽  
Giant Branch Stars

Evolution and Nucleosynthesis in Low‐Mass Asymptotic Giant Branch Stars. I. Formation of Population I Carbon Stars

1997 ◽  
Vol 478 (1) ◽  
pp. 332-339 ◽  
Author(s):  
Oscar Straniero ◽  
Alessandro Chieffi ◽  
Marco Limongi ◽  
Maurizio Busso ◽  
Roberto Gallino ◽  
...  
Keyword(s):  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Carbon Stars ◽  
Low Mass ◽  
Giant Branch Stars
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