Spherical models with constant velocity anisotropy β have distribution functions depending on binding energy E and angular momentum L of the form f (E, L) = L−2β fE(E). An inversion for the unknown function fE (E) is straightforward to derive and reduces to Eddington’s famous algorithm for isotropic models (β = 0). Importantly, if the anisotropy parameter of the model is a half-integer constant...

We explore the sensitivity in open cluster ages obtained by the lithium depletion boundary (LDB) technique to the stellar model input physics. The LDB age technique is limited to open clusters with ages ranging from 20 to 200 Myr. Effective 1-σ errors in the LDB technique due to uncertain input physics are roughly 3% at the oldest age increasing to 7% at the youngest age. Bolometric correction ...

In an effort to test stellar structure and evolution models, analysis of oscillations in A and F stars in open clusters is carried out by the STACC network (Frandsen 1992). In this paper we describe our effort to locate a suitable open cluster in the northern hemisphere for a future multi-site campaign.We present BV Johnson and time series CCDphotometry of four poorly studied open clusters: NGC...

Classifying a time series is fundamental task in temporal analysis. This provides valuable insights into the characteristics of data. Although it has been applied to traffic flow and individual-centered accessibility analysis, yet be place-centered research. In this study, we have proposed an actual isochrone dynamic time-wrapping distance-based k-medoids method tested its applicability bus Usi...

We present an analysis of the many possible methods for simulating and analysing colour-magnitude diagrams, with application to studies of the field halo stellar populations of resolved galaxies. Special consideration is made to the analysis of stars on the Red Giant branch (RGB), and methods for obtaining metallicity distributions for old populations based on analysis of evolved sections of th...

Photometric UBVI CCD photometry is presented for NGC 188 and Berkeley 17. Color-magnitude diagrams (CMDs) are constructed and reach well past the mainsequence turn-off for both clusters. Cluster ages are determined by means of isochrone fitting to the cluster CMDs. These fits are constrained to agree with spectroscopic metallicity and reddening estimates. Cluster ages are determined to be 7.0 ±...

We have used RCIC CCD photometry from the Isaac Newton telescope and intermediate resolution spectroscopy from the Gemini North telescope to identify and characterise low-mass (0.15 < M/M⊙ < 1.3) pre-main sequence stars in the young open cluster NGC 2169. Isochrone fitting to the highand low-mass populations yields an intrinsic distance modulus of 10.13 −0.09 mag and a model-dependent age of 9±...

We present a detailed analysis of the detached eclipsing binary CD Tau. A large variety of observational data, in form of IR photometry, CORAVEL radial velocity observations and high-resolution spectra, are combined with the published light curves to derive accurate absolute dimensions and effective temperature of the components, as well as the metal abundance of the system. We obtain: MA = 1.4...

We have computed the rest-frame comoving luminosity density in various bands as a function of redshift and the cosmic star formation rate (SFR) using a ΛCDM hydrodynamical galaxy simulation. We used an updated isochrone synthesis code to calculate the luminosity density. The calculated UV-luminosity density and the cosmic SFR have a steep rise from z = 0 to 1, a moderate plateau between z = 1 ∼...

We aim to unravel the interior mixing profile of pulsating eclipsing binary KIC9850387 by comparing its dynamical parameters and derived through a combination evolutionary asteroseismic modelling. created grid stellar models using code \textsc{mesa} performed an isochrone-cloud (isocloud) based modelling system. then generated pulsational pulsation \textsc{gyre} on age constraints from Finally,...