相关论文: Rotational mixing in early-type stars: the main-se…
Massive star evolution remains only partly constrained. In particular, the exact role of rotation has been questioned by puzzling properties of OB stars in the Magellanic Clouds. Our goal is to study the relation between surface chemical…
Stellar rotation produces an internal mixing of the elements due to shear instability and meridional circulation. This leads to observable $N/C$ enhancements in massive stars above about 7--9 $M_{\odot}$. Rotation also favours mass loss by…
The main instabilities induced by rotation in stellar interiors are described. We derive from first principles the general equation describing the transport of the angular momentum. The case of the transport of the chemical species is also…
Many observational results seem to indicate more efficient mixing processes in intermediate mass stars (5-20 M$_{\odot}$) than the expected by the standard models. These processes are usually thought to be caused by stellar rotation. Our…
One of the main uncertainties in evolutionary calculations of massive stars is the efficiency of internal mixing. It changes the chemical profile inside the star and can therefore affect the structure and further evolution. We demonstrate…
Stellar rotation significantly shapes the evolution of massive stars, yet the interplay of mass and metallicity remains elusive, limiting our capacity to construct accurate stellar evolution models and to better estimate the impact of…
Chemical turbulent mixing induced by rotation can affect the internal distribution of mu near the energy-generating core of main-sequence stars, having an effect on the evolutionary tracks similar to that of overshooting. However, this…
In this paper we study the effects of rotation in low-mass, low-metallicity RGB stars. We present the first evolutionary models taking into account self-consistently the latest prescriptions for the transport of angular momentum by…
The influence of rotational mixing on the evolution and asteroseismic properties of solar-type stars is studied. Rotational mixing changes the global properties of a solar-type star with a significant increase of the effective temperature…
First, we review the main physical effects to be considered in the building of evolutionary models of rotating stars on the Upper Main-Sequence (MS). The internal rotation law evolves as a result of contraction and expansion, meridional…
Models of rotating single stars can successfully account for a wide variety of observed stellar phenomena, such as the surface enhancements of N and He. However, recent observations have questioned the idea that rotational mixing is the…
Rotation has become an important element in evolutionary models of massive stars, specifically via the prediction of rotational mixing. Here, we study a sample of stars, including rapid rotators, to constrain such models and use nitrogen…
Aims: Past observations of fast-rotating massive stars exhibiting normal nitrogen abundances at their surface have raised questions about the rotational mixing paradigm. We revisit this question thanks to a spectroscopic analysis of a…
In order to investigate the possible influence of rotation on the efficiency of the first dredge-up we determined atmospheric parameters, masses, and abundances of carbon, nitrogen, and oxygen in a sample of evolved intermediate mass stars.…
We investigate the evolution of the surface properties of models for rotating massive stars, i.e., their luminosities, effective temperatures, surface rotational velocities, and surface abundances of all isotopes, from the zero age main…
This article first reviews the basic physics of rotating stars and their evolution. We examine in particular the changes of the mechanical and thermal equilibrium of rotating stars. An important (predicted and observed) effect is that…
Angular momentum is a key property regulating star formation and evolution. However, the physics driving the distribution of the stellar rotation rates of early-type main-sequence stars is as yet poorly understood. Using our catalog of…
At very low metallicity, the effects of differential rotation have a more important impact on the evolution of stars than at high metallicity. Rotational mixing leads to the production of great quantities of helium and of primary $^{14}$N…
We examine the role of rotation on the evolution and chemical yields of very metal--poor stars. The models include the same physics, which was applied successfully at the solar $Z$ and for the SMC, in particular, shear diffusion, meridional…
We present a first set of results concerning stellar evolution of rotating low-mass stars. Our models include fully consistent transport of angular momentum and chemicals due to the combined action of rotation induced mixing (according to…