相关论文: The Evolution of Procyon A

We investigate a selected sample of Galactic classical Cepheids with available distance and reddening estimates in the framework of the theoretical scenario provided by pulsation models, computed with metal abundance Z=0.02, helium content…

We developed angular momentum evolution models for 0.5 and 0.8 $M_{\odot}$ stars. The parametric models include a new wind braking law based on recent numerical simulations of magnetised stellar winds, specific dynamo and mass-loss rate…

Numerical computations of stellar oscillations for models representative of B-type stars predict fewer modes to be excited than observations reveal from modern space-based photometric data. One shortcoming of state-of-the-art evolution…

Frequencies of 13 oscillation modes in the star XX Pyxidis (CD-24 7599) are accurately measured but for none of the modes the spherical harmonic degree l is known. We present results of an attempt to construct the model whose low-l mode…

We review recent results of stellar pulsation modelling that show that even very simple one-dimensional models for time dependent turbulent energy diffusion and convection provide a substantial improvement over purely radiative models.

The chemical enrichment of the Universe; the mass spectrum of planetary nebulae, white dwarfs and gravitational wave progenitors; the frequency distribution of Type I and II supernovae; the fate of exoplanets ... a multitude of phenomena…

The rotation of stars has many interesting and important consequences for the photometric and chemical evolution of galaxies. Many of the predictions of models of stellar rotation are now compared with observations of surface abundances and…

We present a novel approach to model the nearby stars Alpha Cen A & B and Procyon A using asteroseismic and interferometric constraints. Using the VINCI instrument installed at the VLT Interferometer (VLTI), the angular diameters of the…

A continuous set of echelle spectra of TW Hya, taken with the MIKE spectrograph on the Magellan2/Clay telescope at Las Campanas Observatory in April 2006 reveals systematic variations in the flux, velocity, and profile of the H-alpha…

Asteroseismology provides a unique tool for studying stellar interiors. Recently p modes have been detected on the bright solar-like star alpha Cen A thanks to high-precision radial-velocity measurements. However a better characterisation…

The Peccei-Quinn mechanism proposed to solve the CP problem of Quantum Chromodynamics has as consequence the existence of axions, hypothetical weakly interacting particles whose mass is constrained to be on the sub-eV range. If these…

Massive stars and their winds have a large influence in their environment, e.g, determining the accretion rate on to the Galactic Centre (GC) super-massive black hole Sgr A*. The winds of those stars collide and are accreted, at a rate that…

The Microvariability and Oscillations of STars (MOST) photometric satellite has already undertaken more than 64 primary campaigns which include some clusters and has obtained observations of >850 secondary stars of which ~180 are variable.…

We develop analytic approximations to the density evolution of prestellar cores, based on the results of hydrodynamical simulations. We use these approximations as input for a time-dependent gas-grain chemical code to investigate the…

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…

The current study was developed to provide a database of relatively simple numerical simulations of protostellar collapse, as a template library for observations of cores and very young protostars, and for researchers who wish to test their…

We have constructed models for the sun at three stages of its evolution: a zero-age main sequence model, the present sun, and a subgiant model. For each model, the turbulent pressure and turbulent kinetic energy were calculated from 3-d…

Due to their high luminosity at maximum and degree of homogeneity, Type Ia supernovae have been extensively used for cosmological purpouses, in particular to estimate extragalactic distances and the Hubble constant. Recently the number of…

Massive stars play a key role in the evolution of the Universe. Our goal is to compare observed and predicted properties of single Galactic O stars to identify and constrain uncertain physical parameters and processes in stellar evolution…

We provide an extensive set of theoretical spectral energy distributions of massive stars derived from our "combined stellar structure and atmosphere models". The calculations covering the entire main sequence evolution for initial masses…