Abstract: Asymptotic giant branch (AGB) stars are a main site of production of nuclei heavier than iron via the s process. In massive (>4 M⊙) AGB stars the operation of the 22 Ne neutron source appears to be confirmed by observations of high Rb enhancements, while the lack of Tc in these stars rules out 13 C as a main source of neutrons. The problem is that the Rb enhancements are not accompanied by Zr enhancements, as expected by s-process models. This discrepancy may be solved via a better understanding of the complex atmospheres of AGB stars. Sec...
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Topics: 
Astrophysics
Astronomy