Related papers: Pre-main-sequence isochrones -- I. The Pleiades be…
A method is developed for fitting theoretically predicted astronomical spectra to an observed spectrum. Using a hierarchical Bayesian principle, the method takes both systematic and statistical measurement errors into account, which has not…
The determination of the astrophysical properties of stars remains challenging, and frequently relies on the application of stellar models. Stellar sequences in nearby open clusters provide some of the best means to test and calibrate…
Grids of stellar evolution are required in many fields of astronomy/astrophysics, such as planet hosting stars, binaries, clusters, chemically peculiar stars, etc. In this study, a grid of stellar evolution models with updated ingredients…
In this study I assess how existing data for the solar analogues 16 Cyg A and B, in particular the asteroseismic measurements obtained from \emph{Kepler}, constrain theoretical stellar models. The goal is two-fold: first to use these stars…
We consider the evolution of the sky-averaged 21 cm background during the early phases of structure formation. Using simple analytic models, we calculate the thermal and ionization histories, assuming that stellar photons dominate the…
We have selected pre-main-sequence stars in 12 groups of notional ages ranging from 1 Myr to 35 Myrs, using heterogeneous membership criteria. Using these members we have constructed empirical isochrones in V, V-I colour magnitude diagrams…
We present models that predict spectra of old- and intermediate-aged stellar populations at 2.51\AA\ (FWHM) with varying [\alpha/Fe] abundance. The models are based on the MILES library and on corrections from theoretical stellar spectra.…
We present preliminary source counts at 6.7um and 15um from the Preliminary Analysis of the European Large Area ISO survey, with limiting flux densities of \~2mJy at 15um & ~1mJy at 6.7um. We separate the stellar contribution from the…
The epoch of hydrogen reionization is complete by $z=5$, but its progression at higher redshifts is uncertain. Measurements of Ly$\alpha$ forest opacity show large scatter at $z<6$, suggestive of spatial fluctuations in neutral fraction…
We extend our theoretical computations for low-mass stars to intermediate-mass and massive stars, for which few databases exist in the literature. Evolutionary tracks and isochrones are computed from 2.50 to 20 solar masses for agrid of 37…
We pose the question of how much information on the atmospheric parameters of late-type stars can be retrieved purely from colors using standard photometric systems. We carried out numerical experiments using stellar fluxes from model…
Measuring the evolution of X-ray emission from pre-main sequence (PMS) stars gives insight into two issues: the response of magnetic dynamo processes to changes in interior structure and the effects of high-energy radiation on…
Information extracted from the GAIA Data Release 3 is used to examine the stellar contents within projected separations of 10 parsecs from eight close binary systems that are either classical W Serpentis systems or related objects. The goal…
Stellar evolution calculations with variable abundance ratios were used to gauge the effects on temperatures, luminosities, and lifetimes in various phases. Individual elements C, N, O, Mg, Si, and Fe were included. Most of the effect…
A method for measuring the difference between centroids of polarized flux and total flux of an astronomical object - {\it polaroastrometry} - is proposed. The deviation of the centroid of flux corresponding to Stokes parameter $Q$ or $U$…
Color-Magnitude Diagrams (CMDs) are plots that compare the magnitudes (luminosities) of stars in different wavelengths of light (colors). High nonlinear correlations among the mass, color, and surface temperature of newly formed stars…
We present new theoretical models for surface brightness fluctuations in the near-infrared. We show the time evolution of near-infrared brightness fluctuation properties over large age and metallicity ranges, i.e., from 12 Myr to 16 Gyr,…
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…
We introduce the Yale-Potsdam Stellar Isochrones (YaPSI), a new grid of stellar evolution tracks and isochrones of solar-scaled composition. In an effort to improve the Yonsei-Yale database, special emphasis is placed on the construction of…
The inference of stellar parameters (such as radius and mass) through asteroseismic forward modelling depends on the number, accuracy, and precision of seismic and atmospheric constraints. ESA's Gaia space mission is providing precise…