The evolution of asymptotic giant branch stars in the Magellanic Clouds. III - The problem of intermediate-mass stars

1987 ◽  
Vol 321 ◽  
pp. 156 ◽  
Author(s):  
Jeremy Mould ◽  
Neill Reid
Keyword(s):  
Magellanic Clouds ◽  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Intermediate Mass ◽  
Intermediate Mass Stars ◽  
Giant Branch Stars

scholarly journals The Chemical Evolution of Magnesium Isotopic Abundances in the Solar Neighbourhood

2003 ◽  
Vol 20 (4) ◽  
pp. 340-344 ◽  
Author(s):  
Y. Fenner ◽  
B. K. Gibson ◽  
H.-c. Lee ◽  
A. I. Karakas ◽  
J. C. Lattanzio ◽  
...  
Keyword(s):  
Chemical Evolution ◽  
Galactic Disk ◽  
Asymptotic Giant Branch ◽  
Solar Neighbourhood ◽  
Asymptotic Giant Branch Stars ◽  
Intermediate Mass ◽  
Intermediate Mass Stars ◽  
Isotopic Abundances ◽  
First Time ◽  
Giant Branch Stars

AbstractThe abundance of the neutron-rich magnesium isotopes observed in metal-poor stars is explained quantitatively with a chemical evolution model of the local Galaxy that considers — for the first time — the metallicity-dependent contribution from intermediate mass stars. Previous models that simulate the variation of Mg isotopic ratios with metallicity in the solar neighbourhood have attributed the production of 25Mg and 26Mg exclusively to hydrostatic burning in massive stars. These models match the data well for [Fe/H] > –1.0 but severely underestimate 25,26Mg/24Mg at lower metallicities. Earlier studies have noted that this discrepancy may indicate a significant role played by intermediate mass stars. Only recently have detailed calculations of intermediate mass stellar yields of 25Mg and 26Mg become available with which to test this hypothesis. In an extension of previous work, we present a model that successfully matches the Mg isotopic abundances in nearby Galactic disk stars through the incorporation of nucleosynthesis predictions of Mg isotopic production in asymptotic giant branch stars.

scholarly journals Obscured Asymptotic Giant Branch stars in the Magellanic Clouds

1999 ◽  
Vol 191 ◽  
pp. 567-572 ◽  
Author(s):  
Jacco Th. van Loon
Keyword(s):  
Magellanic Clouds ◽  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Agb Stars ◽  
Recent Advances ◽  
Giant Branch Stars

We report on some recent advances in the study and understanding of heavily obscured AGB stars in the Magellanic Clouds.

The First 8–13 Micron Spectra of Asymptotic Giant Branch Stars in the Magellanic Clouds

1995 ◽  
Vol 449 (2) ◽  
Author(s):  
M. A. T. Groenewegen ◽  
C. H. Smith ◽  
P. R. Wood ◽  
A. Omont ◽  
T. Fujiyoshi
Keyword(s):  
Magellanic Clouds ◽  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Giant Branch Stars

scholarly journals Rubidium, zirconium, and lithium production in intermediate-mass asymptotic giant branch stars

2012 ◽  
Vol 540 ◽  
pp. A44 ◽  
Author(s):  
M. A. van Raai ◽  
M. Lugaro ◽  
A. I. Karakas ◽  
D. A. García-Hernández ◽  
D. Yong
Keyword(s):  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Intermediate Mass ◽  
Giant Branch Stars

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

2016 ◽  
Vol 822 (2) ◽  
pp. 73 ◽  
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 ◽  
Intermediate Mass ◽  
Low Metallicity ◽  
Giant Branch Stars

scholarly journals Detection and characteristics of magnetic fields in evolved intermediate mass stars

2014 ◽  
Vol 10 (S305) ◽  
pp. 42-46
Author(s):  
Laurence Sabin
Keyword(s):  
Magnetic Fields ◽  
Point Of View ◽  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Stellar Objects ◽  
Intermediate Mass Stars ◽  
Theoretical Predictions ◽  
The One ◽  
Loss Control ◽  
Giant Branch Stars

AbstractThe role of magnetic fields in late type stars, such as Asymptotic Giant Branch stars (AGBs), Post-AGBs and Planetary Nebulae (PNe), is poorly known from an observational point of view. Magnetic fields are however believed to have a non-negligible influence on the dynamics (via mass loss control, outflows shaping) and even on the chemistry (e.g. extra mixing) of these stellar objects. We are therefore presenting two different types of investigation, both based on the use of polarimetry, which aim at filling the gap between the observations on the one hand and the theoretical predictions on the other hand.

scholarly journals Rapid evolution of [WC] stars in the Magellanic Clouds

2020 ◽  
Vol 642 ◽  
pp. A71
Author(s):  
Marcin Hajduk
Keyword(s):  
South African ◽  
Rapid Evolution ◽  
Planetary Nebulae ◽  
Magellanic Clouds ◽  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Evolutionary Models ◽  
Heating Rates ◽  
Giant Branch Stars ◽  
Central Stars

We obtained new spectra of fourteen Magellanic Cloud planetary nebulae with the South African Large Telescope to determine heating rates of their central stars and to verify evolutionary models of post-asymptotic giant branch stars. We compared new spectra with observations made in previous years. Five planetary nebulae showed an increase in excitation over time. Four of their central stars exhibit [WC] features in their spectra, including three new detections. This raises the total number of [WC] central stars of PNe in the Magellanic Clouds to ten. We compared determined heating rates of the four [WC] central stars with the He-burning post-asymptotic giant branch evolutionary tracks and the remaining star with the H-burning tracks. Determined heating rates are consistent with the evolutionary models for both H and He-burning post-asymptotic giant branch stars. The central stars of the PNe that show the fastest increase of excitation are also the most luminous in the sample. This indicates that [WC] central stars in the Magellanic Clouds evolve faster than H-burning central stars, and they originate from more massive progenitors.

scholarly journals Mass-Losing AGB Stars in the Magellanic Clouds

1993 ◽  
Vol 155 ◽  
pp. 319-319
Author(s):  
Neill Reid
Keyword(s):  
Mass Loss ◽  
Stellar Evolution ◽  
Planetary Nebula ◽  
Luminosity Function ◽  
Magellanic Clouds ◽  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Agb Stars ◽  
The Future ◽  
Giant Branch Stars

Asymptotic giant branch stars are the immediate precursors to the planetary nebula stage of stellar evolution. It is clear that the latter stages of a stars life on the AGB are accompanied by either continuous or episodic mass-loss, with the final convulsion being the ejection of the envelope (the future planetary shell), the gradual exposure of the bare CO core and the rapid horizontal evolution to the blue in the H-R diagram. Thus, the structure of the planetary nebula luminosity function, particularly at the higher luminosities (although this phase is extremely rapid), is intimately tied to the luminosity function of the AGB.

scholarly journals Rb-RICH ASYMPTOTIC GIANT BRANCH STARS IN THE MAGELLANIC CLOUDS

2009 ◽  
Vol 705 (1) ◽  
pp. L31-L35 ◽  
Author(s):  
D. A. García-Hernández ◽  
A. Manchado ◽  
D. L. Lambert ◽  
B. Plez ◽  
P. García-Lario ◽  
...  
Keyword(s):  
Magellanic Clouds ◽  
Asymptotic Giant Branch ◽  
Asymptotic Giant Branch Stars ◽  
Giant Branch Stars
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