S-process nucleosynthesis in low mass AGB Stars: do we really need an improved determination of the 13C(α, n)16O reaction rate?

Thermally pulsing Asymptotic Giant Branch stars are responsible for the nucleosynthesis of the main component of the cosmic s-elements. The most important neutron source is the 13C(α, n)16O reaction. Owing to the presence of a subthreshold resonance, the low energy extrapolation is a rather complex task. The rate quoted in the literature differ up to a factor of 4 at typical stellar energies. The latest improvements in computer power allows us to calculate the evolution of TP-AGB stars coupled with a full nuclear network, extending from hydrogen to lead. Here we discuss the effects of the variation of the 13C(α, n)16O rate on the predicted neutron capture nucleosynthesis