Related papers: Convective H-He Interactions in Massive Population…
The cores of main sequence intermediate- and high-mass stars are convective. Mixing at the radiative-convective boundary, waves excited by the convection, and magnetic fields generated by convective dynamos all influence the main sequence…
The advent of massively parallel supercomputing has begun to permit explicit 3--D simulations of turbulent convection occurring within the cores of early-type main sequence stars. Such studies should complement the stellar structure and…
Motivated by the recent observation by NICER of a type I X-ray burst from SAX J1808.4-3658 with a distinct "pause" feature during its rise (Bult et al. 2019), we show that bursts which ignite in a helium layer underneath a hydrogen-rich…
We study turbulent convection during the core helium flash close to its peak by comparing the results of two and three-dimensional hydrodynamic simulations. We use a multidimensional Eulerian hydrodynamics code based on state-of-the-art…
In young dense clusters repeated collisions between massive stars may lead to the formation of a very massive star (above 100 Msun). In the past the study of the long-term evolution of merger remnants has mostly focussed on collisions…
We construct a two-zone model to describe H and He burning on the surface of an accreting neutron star and use it to study the triggering of type I X-ray bursts. Although highly simplified, the model reproduces all of the bursting regimes…
The relation between the star formation rate and the kinetic energy increase in a region containing a large number of stellar sources is investigated as a possible prescription for star formation feedback in larger scale galaxy evolution…
Novae are cataclysmic variables driven by accretion of H-rich material onto a white-dwarf (WD) star from its low-mass main-sequence binary companion. New time-domain observational capabilities, such as the Palomar Transient Factory and…
We have investigated the role of the convective overshooting on the production of s-nuclei during core He-burning phase in stellar models with different initial mass and metallicity ($15 \leq M_{ZAMS}/M_{\odot} \leq 25$; $10^{-4} \leq Z…
The ${}^{12} \mathrm{C}(\alpha, \gamma)^{16} \mathrm{O}$ reaction is one of the most important reactions in the evolution of massive stars, yet its rate is still highly uncertain. In this work, we investigated how variations in the ${}^{12}…
About a quarter of all post-asymptotic giant branch (AGB) stars are hydrogen-deficient. Stellar evolutionary models explain the carbon-dominated H-deficient stars by a (very) late thermal pulse scenario where the hydrogen-rich envelope is…
We present the first detailed three-dimensional (3D) hydrodynamic implicit large eddy simulations of turbulent convection of carbon burning in massive stars. Simulations begin with radial profiles mapped from a carbon burning shell within a…
Context. The evolution of massive stars is strongly influenced by internal mixing processes such as semiconvection, convective core overshooting, and rotationally induced mixing. None of these is currently well constrained. Aims. We…
The prediction of standard chemical evolution models of higher abundances of He3 at the solar and present-day epochs than are observed indicates a possible problem with the yield of He3 for stars in the range of 1-3 solar masses. Because…
Our ability to predict the structure and evolution of stars is in part limited by complex, 3D hydrodynamic processes such as convective boundary mixing. Hydrodynamic simulations help us understand the dynamics of stellar convection and…
Early-type stars have convective cores due to a steep temperature gradient produced by the CNO cycle. These cores can host dynamos, and the generated magnetic fields can be relevant to explain the magnetism observed in Ap/Bp stars. Our main…
[Shortened] The 12C + 12C fusion reaction has been the subject of considerable experimental efforts to constrain uncertainties at temperatures relevant for stellar nucleosynthesis. In order to investigate the effect of an enhanced carbon…
We present the evolution of a 6M$_{\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…
Convective cores are the hydrogen reservoirs of main sequence stars that are more massive than around 1.2 solar masses. The characteristics of the cores have a strong impact on the evolution and structure of the star. However, such results…
The first stars might have been fast rotators. This would have important consequences for their radiative, mechanical and chemical feedback. We discuss the impact of fast initial rotation on the evolution of massive Population III models…