منابع مشابه
Nucleosynthesis in asymptotic giant branch stars
The nucleosynthesis in asymptotic giant branch stars (briefly: AGB)is a challenging and fascinating subject in the theory of stellar evolution and important for observations as well. This is because about of half the heavy elements beyond iron are synthesized during thermal pulsation phases of these stars. Furthermore, the understanding of the production of the heavy elements and some light ele...
متن کاملBackflow in Post-asymptotic Giant Branch Stars
We derive the conditions for a backflow toward the central star(s) of circumstellar material to occur during the post-asymptotic giant branch (AGB) phase. The backflowing material may be accreted by the post-AGB star and/or its companion, if such exists. Such a backflow may play a significant role in shaping the descendant planetary nebula, by, among other things, slowing down the post-AGB evol...
متن کاملSodium production in asymptotic giant branch stars
A new scenario is presented for the production of 23Na in asymptotic giant branch (AGB) stars. The scenario takes advantage of the periodic third dredge-up episodes characterizing those stars, which mix primary 12C from their intershell layers to their surface. Two successive interpulse/pulse/dredgeup sequences are then required to produce 23Na. During the first sequence carbon and oxygen are c...
متن کاملMagnetic Flares on Asymptotic Giant Branch Stars
We investigate the consequences of magnetic flares on the surface of asymptotic giant branch (AGB) and similar stars. In contrast to the solar wind, in the winds of AGB stars the gas cooling time is much shorter than the outflow time. As a result, we predict that energetic flaring should enhance, rather than inhibit, dust formation around AGB stars. Analysis of an archival ROSAT X-ray spectrum ...
متن کاملMagnetic Mixing in Red Giant and Asymptotic Giant Branch Stars
The available information on isotopic abundances in the atmospheres of low-mass Red Giant Branch (RGB) and Asymptotic Giant Branch (AGB) stars requires that episodes of extensive mixing occur below the convective envelope, reaching down to layers close to the hydrogen burning shell (Cool Bottom Processing). Recently Busso et al. (2007) suggested that dynamo-produced buoyant magnetic flux tubes ...
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ژورنال
عنوان ژورنال: Nature
سال: 1992
ISSN: 0028-0836,1476-4687
DOI: 10.1038/359018b0