Related papers: Convective Core Overshoot & Mass Loss in Classical…
In spite of the great effort made in the last decades to improve our understanding of stellar evolution, significant uncertainties remain due to our poor knowledge of some complex physical processes that require an empirical calibration,…
Cepheid masses derived from pulsations or binary dynamics are generally lower than those derived from stellar evolution models. Recent efforts have been dedicated to investigating the effects of abundances, mass loss, rotation, convection…
Overshooting from the convective cores of stars more massive than about 1.2 M(Sun) has a profound impact on their subsequent evolution. And yet, the formulation of the overshooting mechanism in current stellar evolution models has a free…
In our SCUBA survey of Perseus, we find that the fraction of protostellar cores increases towards higher masses and the most massive cores are all protostellar. In this paper we consider the possible explanations of this apparent mass…
We discuss the effects of convective overshooting in the PMS evolution of intermediate mass stars, by analysing in detail the early evolution towards the main sequence of a 2 M_sun stellar model. These effects can be extremely important in…
We use models of coupled thermal evolution and photo-evaporative mass loss to understand the formation and evolution of the Kepler-36 system. We show that the large contrast in mean planetary density observed by Carter et al. (2012) can be…
Context: Internal chemical mixing in intermediate- and high-mass stars represents an immense uncertainty in stellar evolution models.In addition to extending the main-sequence lifetime, chemical mixing also appreciably increases the mass of…
Polaris is one of the most observed stars in the night sky, with recorded observations spanning more than 200 years. From these observations, one can study the real-time evolution of Polaris via the secular rate of change of the pulsation…
[Abridged] We aim to improve the understanding of Cepheids from an evolutionary perspective and establish the role of rotation in the Cepheid paradigm. In particular, we are interested in the contribution of rotation to the problem of…
Convective core overshooting has a strong influence on the evolution of stars of moderate and high mass. Studies of double-lined eclipsing binaries and stellar oscillations have renewed interest in the possible dependence of overshooting on…
Some physical processes that occur during a star's main-sequence evolution also affect its post main-sequence evolution. It is well known that stars with masses above approximately 1.1 $M_{\odot}$ have well-mixed convective cores on the…
Masses determined from classical Cepheids in binary systems are a primary test of both pulsation and evolutionary calculations. The first step is to determine the orbit from ground-based radial velocities. Complementary satellite data from…
Modern tools for modeling stellar evolution, such as MESA (Modules for Experiments in Stellar Astrophysics), offer state-of-the-art implementations of stellar theories. However, this parametric approach introduces many free parameters that…
Many current stellar evolution models assume some dependence of the strength of convective core overshooting on mass for stars more massive than 1.1-1.2 solar masses, but the adopted shapes for that relation have remained somewhat arbitrary…
Context. Mixing by convective overshooting has long been suggested to play an important role for the amount of hydrogen available to nuclear burning in convective cores of stars. The best way to model this effect is still debated. Aims. We…
Analyses of recent observations of the sole classical Cepheid in the Kepler field, V1154 Cygni, found random changes of about 30 minutes in the pulsation period. These period changes challenge standard theories of pulsation and evolution…
The $\beta$ Cephei stars represent an important class of massive star pulsators probing the evolution of B-type stars and the transition from main sequence to hydrogen-shell burning evolution. By understanding $\beta$ Cep stars, we gain…
Mass loss and variability are two linked, fundamental properties of evolved stars. In this paper I review our current understanding of these processes, with a particular focus on how observations and models are used to constrain reliable…
A one-dimensional turbulent convection model in the form of a time-dependent diffusion equation for the turbulent energy is incorporated into our numerical pulsation code. The effect of turbulent convection on the structural rearrangement…
It has been observed that Cepheids in the Magellanic Clouds have lower masses for the same luminosity than those in the Milky Way. The model, from Neilson & Lester (2008), of pulsation-driven mass loss for Cepheids is applied to theoretical…