Related papers: Evolutionary implications of the new triple-alpha …
Recently, the triple-\alpha (3\alpha) process, by which three 4He nuclei are fused into a 12C nucleus in stars, was studied by different methods in solving the quantum mechanical three-body problem. Their results of the thermonuclear…
One of the largest uncertainties in stellar evolutionary computations is the accuracy of the considered reaction rates. The 12C(alpha,gamma)16O reaction is particularly important for the study of low- and intermediate-mass stars as it…
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…
We investigate the effects of thermonuclear reaction rate variations on 26Al production in massive stars. The dominant production sites in such events were recently investigated by using stellar model calculations: explosive neon-carbon…
We present the evolution of a 6M$_{\odot}$ star, of solar-like initial metallicity, and investigate the effects of key nuclear reaction rates, as well as the treatment of the convective mixing on its evolution along the Cepheid instability…
The relevant energy ranges for stellar nuclear reactions are introduced. Low-energy compound and direct reactions are discussed. Stellar modifications of the cross sections are presented. Implications for experiments are outlined.
Helium burning is one of the most fundamental steps of stellar nucleosynthesis, as it describes the formation of life-determining element of carbon, while it plays a key role in the evolution of Red Giant, accreting White Dwarfs and Neutron…
Through the triple-alpha process occurring in red giant stars the bulk of the carbon existing in our universe is produced. We calculated the change of the triple-alpha reaction rate for slight variations of the nucleon-nucleon force using a…
The bulk of the carbon in our universe is produced in the triple-alpha process in helium-burning red giant stars. We calculated the change of the triple-alpha reaction rate in a microscopic 12-nucleon model of the C-12 nucleus and looked…
Over the last three years, the rates of all the main nuclear reactions involving the destruction and production of $^{26}$Al in stars ($^{26}$Al(n, p)$^{26}$Mg, $^{26}$Al(n, $\alpha$)$^{23}$Na, $^{26}$Al(p, $\gamma$)$^{27}$Si and…
Type-I X-ray bursts can be used to determine properties of accreting neutron stars via comparisons between model calculations and astronomical observations, exploiting the sensitivity of models to astrophysical conditions. However, the…
Preliminary results of a new set of stellar evolution and nucleosynthesis calculations for massive stars are presented. These results were obtained with an extended reaction network up to Bi. The discussion focuses on the importance of…
Nuclear reactions drive the stellar evolution and contribute to the stellar and galactic chemicals abundances. New determinations of the nuclear reaction rates for key fusion reactions of stellar evolution are now available, paving the way…
We investigate the dependence of the carbon and oxygen production in stars on the 3-alpha rate by varying the energy of the 02+-state of 12C and determine the resulting yields for a selection of low-mass, intermediate-mass, and massive…
Nucleosynthesis in evolved (RGB and AGB) low-mass stars is reviewed under the light of the reaction rates recommended in the NACRE compilation (Angulo et al. 1999). We use a parametric model of stellar nucleosynthesis to investigate the…
This chapter will go through the important nuclear reactions in stellar evolution and explosions, passing through the individual stellar burning stages and also explosive burning conditions. To follow the changes in the composition of…
Properties of atomic nuclei important for the prediction of astrophysical reaction rates are reviewed. In the first part, a recent simulation of evolution and nucleosynthesis of stars between 15 and 25 solar masses is presented. This study…
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…
A variation of the fundamental constants is expected to affect the thermonuclear rates important for stellar nucleosynthesis. In particular, because of the very small resonant energies of Be8 and C12, the triple $\alpha$ process is…
We investigate the influence of both a new generation of low-temperature opacities and of various amounts of alpha-element enhancements on stellar evolution models. New stellar models with two different alpha-element mixtures and two sets…