Related papers: Open Questions in Stellar Helium Burning Addressed…
The rate of oxygen formation determines the C/O ratio during stellar helium burning. It is the single most important nuclear input of stellar evolution theory including the evolution of Type II and Type Ia supernova. Yet the low energy…
Effective values for the key helium burning reaction rates, triple-alpha and 12C(alpha,gamma)16O, are obtained by adjusting their strengths so as to obtain the best match with the solar abundance pattern of isotopes uniquely or…
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…
Nuclear reactions transform atomic nuclei inside stars. This is the process of stellar nucleosynthesis. The basic concepts of determining nuclear reaction rates inside stars are reviewed. How stars manage to burn their fuel so slowly most…
The creation of carbon and oxygen in our universe is one of the forefront questions in nuclear astrophysics. The determination of the abundance of these elements is key to both our understanding of the formation of life on earth and to the…
We follow the evolution of helium stars of initial mass $(2.2 - 2.5) M_\odot$, and show that they undergo off-center carbon burning, which leaves behind ${\mathbf \sim 0.01 M_\odot}$ of unburnt carbon in the inner part of the core. When the…
Light curves, explosion energies, and remnant masses are calculated for a grid of supernovae resulting from massive helium stars that have been evolved including mass loss. These presupernova stars should approximate the results of binary…
We explore the hypothesis, that helium stars in a certain mass range can evolve to a carbon core explosion similar to what is widely accepted as an explanation for the SN I phenomenon. This should happen when their carbon-oxygen core grows…
We review the status of the 12C(a,g)16O reaction rate, of importance for stellar processes in a progenitor star prior to a super-nova collapse. Several attempts to constrain the p-wave S-factor of the 12C(a,g)16O reaction at Helium burning…
We study the sensitivity of presupernova evolution and supernova nucleosynthesis yields of massive stars to variations of the helium-burning reaction rates within the range of their uncertainties. We use the current solar abundances from…
Type Ia supernovae (SN Ia) are the most important standard candles for measuring the expansion history of the universe. The thermonuclear explosion of a white dwarf can explain their observed properties, but neither the progenitor systems…
Type Ia supernovae (SNe Ia) are manifestations of stars deficient of hydrogen and helium disrupting in a thermonuclear runaway. While explosions of carbon-oxygen white dwarfs are thought to account for the majority of events, part of the…
During the early evolution of an AM CVn system, helium is accreted onto the surface of a white dwarf under conditions suitable for unstable thermonuclear ignition. The turbulent motions induced by the convective burning phase in the He…
Thermonuclear supernovae are the result of the violent unbinding of a white dwarf, but the precise nature of the explosion mechanism(s) is a matter of active debate. To this end, several specific scenarios have been proposed to explain the…
For a long time Gerry Brown and his collaborator Hans Bethe considered the question of the final fate of a core collapse (Type II) supernova. Recalling ideas from nuclear structure on Kaon condensate and a soft equation of state of the…
Much difficulty has so far prevented the emergence of a consistent scenario for the origin of Type Ib and Ic supernovae (SNe). Here, we follow a heuristic approach by examining the fate of helium stars in the mass range 4 to 12Msun, which…
(abridged) When stripped from their hydrogen-rich envelopes, stars with initial masses between $\sim$7 and 11 M$_\odot$ develop massive degenerate cores and collapse. Depending on the final structure and composition, the outcome can range…
Stellar cores may be considered as a nuclear reactor that play important role in injecting new synthesized elements in the interstellar medium Helium burning is an important stage that contribute to the synthesis of key elements such as…
The essential ingredients of nuclear astrophysics are the thermonuclear reactions which shape the life and death of stars and which are responsible for the synthesis of the chemical elements in the Universe. Deep underground in the Gran…
Atomic nuclei are transformed into each other in the cosmos by nuclear reactions inside stars: -- the process of nucleosynthesis. The basic concepts of determining nuclear reaction rates inside stars and how they manage to burn their fuel…