Related papers: Semi-convection: What is the underlying physical c…
Semi-convection is a slow mixing process in chemically-inhomogeneous radiative interiors of stars. In massive OB stars, it is important during the main sequence. However, the efficiency of this mixing mechanism is not properly gauged yet.…
Mixing processes such as convection, overshooting and rotational mixing have long been known to affect the evolutionary properties of low-mass stars. While modeling a 1.2 Msun star, we encountered a semiconvective region outside the fully…
A model is developed for the transport of heat and solute in a system of double-diffusive layers under astrophysical conditions (viscosity and solute diffusivity low compared with the thermal diffusivity). The process of formation of the…
The partial mixing of matter between the radiative envelope and the convective core in the early type B--star produces an additional increase of star luminosity during the main sequence evolution. The high quality data on stellar mass and…
It is shown that the unusual thermodynamic properties of matter within the region of two-phase coexistence in hybrid stars result in a change of the standard condition for beginning of convection. In particular, the thermal flux transported…
Semiconvection - mixing that occurs in regions that are stable when considering compositional gradients, but unstable when ignoring them - is shown to have the greatest potential impact on main sequence stars with masses in the range 1.2 -…
Semiconvection occurs in regions of stars and planets that are unstable to overturning convection according to the Schwarzschild criterion, yet stable according to the Ledoux criterion. Previous simulations in Cartesian boxes have advanced…
Convection is ubiquitous in stars and occurs under many different conditions. Here we explore convection in main-sequence stars through two lenses: dimensionless parameters arising from stellar structure and parameters which emerge from the…
The process referred to as "semi-convection" in astrophysics and "double-diffusive convection in the diffusive regime" in Earth and planetary sciences, occurs in stellar and planetary interiors in regions which are stable according to the…
The convective envelopes of solar-type stars and the convective cores of intermediate- and high-mass stars share boundaries with stable radiative zones. Through a host of processes we collectively refer to as "convective boundary mixing"…
In this paper, four sets of evolutionary models are computed with different values of the mixing length parameter $\alpha_{\rm p}$ and the overshooting parameter $\delta_{\rm ov}$. The properties of the convective cores and the convective…
We report on the discovery of an instability in low mass stars just above the threshold ($\sim 0.35 \textrm{M}_{\odot}$) where they are expected to be fully convective on the main sequence. Non-equilibrium He3 burning creates a convective…
A brief review of the current status of neutrino mixing and oscillations in astrophysical environments, with particular emphasis on the Sun and core-collapse supernovae, is given. Implications of the existence of sterile states which mix…
During their main sequence evolution, massive stars can develop convective regions very close to their surface. These regions are caused by an opacity peak associated with iron ionization. Cantiello et al. (2009) found a possible connection…
Solar-like oscillations are excited stochastically by convection. They occur in stars with an outer convection zone, which includes the Sun and other stars on the lower main sequence, as well as cool subgiants and red giants. This chapter…
During most stages of stellar evolution the nuclear burning of lighter to heavier elements results in a radial composition profile which is stabilizing against buoyant acceleration, with light material residing above heavier material.…
Thanks to significant improvements in high-resolution spectrographs and the launch of dedicated space missions MOST, CoRoT and Kepler, the number of subgiants and red-giant stars with detected oscillations has increased significantly over…
Oscillations of the Sun and solar-like stars are believed to be excited stochastically by convection near the stellar surface. Theoretical modeling predicts that the resulting amplitude increases rapidly with the luminosity of the star.…
We examine the convective core helium burning phase of intermediate mass stars, and investigate the role of coupling of nuclear burning and mixing on the extension and duration of the blue loop phase. We compare the theoretical scenario…
Thermal convection is one of the main mechanisms of heat transport and mixing in stars in general and also in the photospheric layers which emit the radiation that we observe with astronomical instruments. The present lecture notes first…