Related papers: Age and convective core overshooting calibrations …
Evolutionary tracks for 2-8M$_\odot$ models, covering a [Fe/H]=$-$1.0 ($Z=0.0014$) to [Fe/H]=+0.2 ($Z=0.02$) metallicity range are computed with Modules for Experiments in Stellar Astrophysics, MESA, to investigate evolutionary and…
We propose a novel method for determining the ages of low-mass, pre-main sequence stellar systems using the apsidal motion of low-mass detached eclipsing binaries. The apsidal motion of a binary system with an eccentric orbit provides…
Stellar evolution models of B-type stars are still uncertain in terms of internal mixing properties, notably in the area between the convective core and the radiative envelope. This impacts age determination of such stars in addition to the…
The LMC clusters are unique templates of simple stellar population (SSP), being crucial to calibrate models describing the integral light as well as to test the stellar evolution theory. With this in mind we analyzed HST/WFPC2 (V, B--V)…
We present a new method for determining the age of late-K type pre-main sequence (PMS) stars by deriving their surface gravity from high-resolution I-band spectroscopy. Since PMS stars contract as they evolve, age can be estimated from…
The unprecedented quality of the asteroseismic data of solar-type stars made available by space missions such as NASA's Kepler telescope are making it possible to explore stellar interior structures. This offers possibilities of…
The detection and analysis of oscillations in binary star systems is critical in understanding stellar structure and evolution. This is partly because such systems have the same initial chemical composition and age. Solar-like oscillations…
Helioseismic investigation has suggested to apply the turbulent convection models (TCMs) to the convective overshooting. Using the turbulent velocity in the overshooting region determined by the TCM, one can deal with the overshooting…
A lithium depletion boundary is detected in HIP 112312 (GJ 871.1 A and B), a \~12 Myr old pre-main sequence binary system. A strong (EW 300 mA) Li 6708 A absorption feature is seen at the secondary (~M4.5) while no Li 6708 A feature is…
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,…
The asteroseismic modelling of period spacing patterns from gravito-inertial modes in stars with a convective core is a high-dimensional problem. We utilise the measured period spacing pattern of prograde dipole gravity modes (acquiring…
We have produced detailed evolutionary models of the binary EK Cep using the CESAM stellar evolution code (Morel 1997). A $\chi^2$-minimisation was performed to derive the most reliable set of modelling parameters. We have found that an…
Studies of cool white dwarfs in the solar neighbourhood have placed a limit on the age of the Galactic disk of 8-9 billion years. However, determining their cooling ages requires the knowledge of their effective temperatures, masses, radii,…
The semi-detached eclipsing binary system, TT Hor, has a $\delta$ Sct primary component (accretor) accreting mass from the secondary star (donor). We fit an eclipsing binary model from V, B and I photometry combined with spectroscopy using…
We have identified a large number of possible very low mass members of the cluster IC2391 based primarily on their location in an I versus (R-I)_C CM diagram. We have obtained new photometry and low resolution ($\Delta \lambda = 2.7$ \AA)…
Asteroseismology of solar-like oscillations in giant stars allow the derivation of their masses and radii. For members of open clusters this allows an age estimate of the cluster which should be identical to the age estimate from the…
In this study, we applied Al-Wardat's method to analyze the subgiant system HIP72217 for which we obtained accurate parameters including stellar masses, effective temperatures ($T_{\text{eff}}$) and system age.For the primary component we…
I present results from an optical spectroscopic investigation of the binary system HD 42401 (V1388 Ori; B2.5 IV-V + B3 V). A combined analysis of V-band photometry and radial velocities indicates that the system has an orbital period of…
We present new V-band differential brightness measurements as well as new radial-velocity measurements of the detached, circular, 0.84-day period, double-lined eclipsing binary system CV Boo. These data along with other observations from…
(Abridged) Highly unequal-mass ratio binaries are rare among field brown dwarfs, with the known census described by q^(4.9+/-0.7). However, such systems can test the joint accuracy of evolutionary and atmospheric models, under the…