The present study examines research undertaken recently to investigate the possibility of the formation of low-mass s-enriched stars ascending the AGB. A first approximation is made to the mechanism of the dredge-up of s-processed material during the interpulse period between two subsequent He thermal instabilites. Several peculiarities of the s-processing concerning the problems of the Kr-85 and Zr-95 branchings are discussed. The production of the long-lived isotopes Zr-93 and Tc-99 is shown to be efficient. The successful reproduction of the whole solar system distribution of s-isotopes by low-mass AGB stars is discussed. The results of the present n-capture nucleosynthesis calculations are compared with the observations of C and s-isotopes on the photospheres of AGB stars, and satisfactory agreement is found.
Nucleosynthesis and dredge-up of carbon and s-process elements in AGB stars
BUSSO, Maurizio Maria;
1990
Abstract
The present study examines research undertaken recently to investigate the possibility of the formation of low-mass s-enriched stars ascending the AGB. A first approximation is made to the mechanism of the dredge-up of s-processed material during the interpulse period between two subsequent He thermal instabilites. Several peculiarities of the s-processing concerning the problems of the Kr-85 and Zr-95 branchings are discussed. The production of the long-lived isotopes Zr-93 and Tc-99 is shown to be efficient. The successful reproduction of the whole solar system distribution of s-isotopes by low-mass AGB stars is discussed. The results of the present n-capture nucleosynthesis calculations are compared with the observations of C and s-isotopes on the photospheres of AGB stars, and satisfactory agreement is found.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
