Related papers: Testing stellar evolution models with the retired …
Doppler-based planet surveys have shown that, besides metallicity, the planet occurrence is also correlated with stellar mass, increasing from M to F-A spectral types. However, it has recently been argued that the subgiants (which represent…
We report here an analysis of the physical stellar parameters of the giant star HD185351 using Kepler short-cadence photometry, optical and near infrared interferometry from CHARA, and high-resolution spectroscopy. Asteroseismic…
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…
Theoretical stellar evolution models are constructed and tailored to the best known, observationally derived characteristics of metal-poor ([Fe/H]$\sim-2.3$) stars representing a range of evolutionary phases: subgiant HD140283, globular…
Using the Yale stellar evolution code, models of mu Her based on asteroseismic measurements are constructed. A $\chi^{2}$ minimization is performed to approach the best modeling parameters which reproduce the observations within their…
Core overshoot is a large source of uncertainty in constructing stellar models. Whether the amount of overshoot is constant or mass dependent is not completely known, even though models sometimes assume a mass-based trend. In this work we…
Accurate determinations of masses and radii in binary stars, along with estimates of the effective temperatures, metallicities, and other properties, have long been used to test models of stellar evolution. As might be expected,…
Doppler-based planet surveys point to an increasing occurrence rate of giant planets with stellar mass. Such surveys rely on evolved stars for a sample of intermediate-mass stars (so-called retired A stars), which are more amenable to…
The main scope of this paper is to investigate the possible existence of a metallicity dependence of the overshooting from main sequence stars turbulent cores. We focus on objects with masses in the range ~2.5 Msol - ~25 Msol. Basically,…
A major weakness in one-dimensional (1D) stellar structure and evolution modeling is the simplified treatment of convection, which leads to erroneous near-surface stratification and considerable uncertainties in predicted effective…
The precise measurement of the masses and radii of stars in eclipsing binary systems provides a window into uncertain processes in stellar evolution, especially mixing at convective boundaries. Recently, these data have been used to…
As part of a larger program aimed at better quantifying the uncertainties in stellar computations, we attempt to calibrate the extent of convective overshooting in low to intermediate mass stars by means of eclipsing binary systems. We…
A new set of stellar models in the mass range 1.2 to 9 $M_{\odot}$ is presented. The adopted chemical compositions cover the typical galactic values, namely $0.0001 \le Z \le 0.02$ and $0.23 \le Y \le 0.28$. A comparison among the most…
Stellar evolution calculations have had great success reproducing the observed atmospheric properties of different classes of stars. Recent detections of g-mode pulsations in evolved He burning stars allow a rare comparison of their…
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…
Convective boundary mixing (CBM) is ubiquitous in stellar evolution. It is a necessary ingredient in the models in order to match observational constraints from clusters, binaries and single stars alike. We compute `effective overshoot'…
Convective overshoot mixing is a critical ingredient of stellar structure models, but is treated in most cases by ad hoc extensions of the mixing-length theory for convection. Advanced theories which are both more physical and numerically…
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…
Over the last decades, several independent studies have shown the need for large convective boundary mixing (CBM) and convective core sizes in massive stars to reproduce a variety of their observed properties. Yet, stars more massive than…
The spectroscopic and photometric analysis of sample Am stars are carried out to determine the stellar characteristics of each studied star. The CCD photometric analysis of HD 98851 and HD 207561 show clear evidence of pulsation variability…