Related papers: Thermonuclear reaction rate of 18O(p,gamma)19F
The thermonuclear $^{19}$F($p$,$\alpha_0$)$^{16}$O reaction rate in a temperature region of 0.007--10 GK has been derived by re-evaluating the available experimental data, together with the low-energy theoretical $R$-matrix extrapolations.…
We present detailed models of low and intermediate-mass asymptotic giant branch (AGB) stars with and without the 18F(a,p)21Ne reaction included in the nuclear network, where the rate for this reaction has been recently experimentally…
The 16O(p,gamma)17F reaction rate is revisited with special emphasis on the stellar temperature range of T=60-100 MK important for hot bottom burning in asymptotic giant branch (AGB) stars. We evaluate existing cross section data that were…
In this review we outline our knowledge on slow neutron captures, concentrating on its main part occurring during the final stages of stellar evolution for low or intermediate-mass stars when they evolve during the Asymptotic Giant Branch,…
We present computations of nucleosynthesis in low-mass red-giant-branch and asymptotic-giant-branch stars of Population I experiencing extended mixing. We adopt the updated version of the FRANEC evolutionary model, a new post-process code…
The recent experimental evaluation of the 18F(a,p)21Ne reaction rate, when considering its associated uncertainties, presented significant differences compared to the theoretical Hauser-Feshbach rate. This was most apparent at the low…
Many nucleosynthesis and mixing processes of low-mass stars as they evolve from the Main Sequence to the thermal-pulse Asymptotic Giant Branch phase (TP-AGB) are well understood (although of course important physics components, e.g.…
Contrary to previous expectations, recent evolutionary models of zero-metallicity stars show that the development of mixing episodes at the beginning of the AGB phase allows low- and intermediate-mass stars to experience thermal pulses. If…
We present nucleosynthesis calculations and the resulting 19F stellar yields for a large set of models with different masses and metallicity. We find that the production of fluorine depends on the temperature of the convective pulses, the…
We present a new measurement of the $\alpha$-spectroscopic factor ($S_\alpha$) and the asymptotic normalization coefficient (ANC) for the 6.356 MeV 1/2$^+$ subthreshold state of $^{17}$O through the $^{13}$C($^{11}$B, $^{7}$Li)$^{17}$O…
A new thermonuclear $^{17}$O($n$,$\gamma$)$^{18}$O rate is derived based on a complete calculation of the direct-capture (DC) and resonant-capture contributions, for a temperature region up to 2 GK of astrophysical interest. We have firstly…
(Abridged) We examine the effects of cool bottom processing (CBP) on several isotopic ratios in the convective envelope during the TP-AGB phase of evolution in a 1.5 M_sun initial-mass star of solar initial composition. We use a parametric…
We explore modifications to the current scenario for the slow neutron capture process in asymptotic giant branch (AGB) stars to account for the Pb deficiency observed in post-AGB stars of low metallicity ([Fe/H] ~ -1.2) and low initial mass…
We present a review of the main phases of stellar evolution with particular emphasis on the nucleosynthesis and mixing mechanisms in low- and intermediate-mass stars. In addition to explicit studies of the effects of the first, second and…
We present stellar evolutionary tracks and nucleosynthetic predictions for a grid of stellar models of low- and intermediate-mass asymptotic giant branch (AGB) stars at $Z=0.001$ ([Fe/H]$=-1.2$). The models cover an initial mass range from…
The s-process in AGB stars produces elements with atomic mass numbers $A\gtrsim60$ through successive neutron captures and beta decays. In stellar environments where the s-process occurs, neutrons quickly thermalize, adopting a…
The NO cycle takes place in the deepest layer of a H-burning core or shell, when the temperature exceeds T {\simeq} 30 {\cdot} 106 K. The O depletion observed in some globular cluster giant stars, always associated with a Na enhancement,…
The reaction $^{17}$O$(p,\gamma)^{18}$F influences hydrogen-burning nucleosynthesis in several stellar sites, such as red giants, asymptotic giant branch (AGB) stars, massive stars and classical novae. In the relevant temperature range for…
The oldest stars hide information about the chemical evolution of the early universe. In this contect new models of the AGB stellar evolution phase at very low and zero metallicity are presented. Due to the deficiency or absence of CNO…
The 14C(alpha,gamma) reaction rate at temperatures below 0.3 GK depends on the properties of two near threshold resonances in 18O, the 1- at 6.198 MeV and the 3- at 6.404 MeV. The alpha+14C Asymptotic Normalization Coefficients (ANCs) for…