Related papers: Evolutionary implications of the new triple-alpha …
We discuss three effects of axial rotation at low metallicity. The first one is the mixing of the chemical species which is predicted to be more efficient in low metallicity environments. A consequence is the production of important…
Nuclear reaction rates are one of the most important ingredients in describing how stars evolve. The study of the nuclear reactions involved in different astrophysical sites is thus mandatory to address most questions in nuclear…
It has been suggested that hydrogen ingestion into the helium shell of massive stars could lead to high $^{13}$C and $^{15}$N excesses when the shock of a core-collapse supernova passes through its helium shell. This prediction questions…
Explosive nuclear burning in astrophysical environments produces unstable nuclei which again can be targets for subsequent reactions. In addition, it involves a large number of stable nuclides which are not fully explored by experiments,…
We discuss recent models on the evolution of massive stars at very low metallicity including the effects of rotation, magnetic fields and binarity. Very metal poor stars lose very little mass and angular momentum during the main sequence…
We discuss theoretical predictions concerning the evolution of globular cluster Pop.II stars vis-a-vis current estimates of standard errors in the determination of nuclear burning rates. Numerical evaluations are given for the dependence of…
In order to study the processes creating intermediate and heavy nuclei in massive stars it is necessary to provide neutron capture cross sections and reaction rates close to stability and for moderately unstable neutron-rich nuclei.…
We present here results of stellar evolution calculations that include the latest advances in radiative opacities and neutrino cooling, and discuss on the basis of these models how the internal stellar structure responds to mass-loss from…
Efforts to understand the origin and growth of massive black holes observed in the early Universe have spurred a strong interest in the evolution and fate of rapidly-accreting primordial (metal-free) stars. Here, we investigate the…
Weak interaction rates on titanium isotopes are important during the late phases of evolution of massive stars. A search was made for key titanium isotopes from available literature and a microscopic calculation of weak rates of these…
The cosmic production of the short-lived radioactive nuclide 26Al is crucial for our understanding of the evolution of stars and galaxies. However, simulations of the stellar sites producing 26Al are still weakened by significant nuclear…
Many of the short-lived radioactive nuclei that were present in the early Solar System can be produced in massive stars. In the first paper in this series (Brinkman et al. 2019), we focused on the production of $^{26}$Al in massive…
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 dense stars the nuclear reaction rates are influenced by screening effects arising from both ions and electrons. In this paper we calculate the enhancement factors due to electron polarization in the high-density, degenerate and…
The prediction of stellar ($\gamma$,$\alpha$) reaction rates for heavy nuclei is based on the calculation of ($\alpha$,$\gamma$) cross sections at sub-Coulomb energies. These rates are essential for modeling the nucleosynthesis of so-called…
We discuss the influence of the 12C(alpha,gamma)16O$ reaction rate on the central He burning of stars in the mass range 0.8-25 Msun, as well as its effects on the explosive yields of a 25 Msun star of solar chemical composition. We find…
Observations of stellar CNO isotope ratios indicate the presence of additional mixing processes on the red giant branch. An estimate of the resulting stellar He-3 depletion is made, as a function of stellar mass and metallicity. Based on…
In recent papers Mannucci et al. (2005, 2006) suggested, on the basis of observational arguments, that there is a bimodal distribution of delay times for the explosion of Type Ia SNe. In this paper, we test this hypothesis in models of…
The reactions that destroy 26Al in massive stars have significance in a number of astrophysical contexts. We evaluate the reaction rates of 26Al(n,p)26Mg and 26Al(n,a)23Na using cross sections obtained from the codes EMPIRE and TALYS. These…
Carbon is produced during the helium burning phase of sufficiently massive stars through the triple alpha process. The $0^+$ energy level of the carbon nucleus allows for resonant nuclear reactions, which act to greatly increase the carbon…