Related papers: Testing stellar evolution models with the retired …
Large spectroscopic surveys of the Milky Way need to be calibrated against a sample of benchmark stars to ensure the reliable determination of atmospheric parameters. We present new fundamental stellar parameters of seven giant and subgiant…
We discuss the internal structure of stars in the mass range 1.5 to 4 M_sun from the PMS to the subgiant phase with a particular emphasis on the convective core and the convective superficial layers. Different physical aspects are…
Mass and momentum exchanges in close massive binaries play an important role in their evolution, and produce several observational signatures such as asynchronous rotation and altered chemical compositions, that remain after the stars…
M-dwarf stars are the most numerous stars in the Universe; they span a wide range in mass and are in the focus of ongoing and planned exoplanet surveys. To investigate and understand their physical nature, detailed spectral information and…
The frequency ratios and of HD 49933 exhibit an increase at high frequencies. This behavior also exists in the ratios of other stars, which is considered to result from the low signal-to-noise ratio and the larger line width at the…
We present a chemical abundance analysis of seven A-type stars with no detailed chemical abundance measurements in the literature. High-resolution spectra of the targets HD 2924, HD 4321, HD 26553, HD 125658, HD 137928, HD 154713, and HD…
White dwarf asteroseismology offers the opportunity to probe the structure and composition of stellar objects governed by relatively simple physical principles. The observational requirements of asteroseismology have been addressed by the…
I present a discussion of fundamental stellar parameters and their observational determination in the context of interferometric measurements with current and future optical/infrared interferometric facilities. Stellar parameters and the…
The chemical composition of high redshift galaxies is an important property which gives clues to their past history and future evolution and yet is difficult to measure with current techniques. In this paper we investigate new metallicity…
By adopting the recently empirically derived dependence of $\alpha$-elements on $[\alpha/{\rm Fe}]$ instead of the conventionally applied uniform one, we tested the agreement between stellar model predictions and observations for red giant…
Based on detailed 2D numerical radiation hydrodynamics (RHD) calculations of time-dependent compressible convection, we have studied the dynamics and thermal structure of the convective surface layers of solar-type stars. The RHD models…
The Hipparcos mission has made it possible to constrain the positions of nearby field stars in the colour-magnitude diagram with very high accuracy. These positions can be compared with the predictions of stellar evolutionary calculations…
Aims. We aim to provide observational constraints on diffusion models that predict peculiar chemical abundances in the atmospheres of Am stars. We also intend to check if chemical peculiarities and slow rotation can be explained by the…
We complement the PARSEC data base of stellar evolutionary tracks with new models of massive stars, from the pre-main sequence phase to the central carbon ignition. We consider a broad range of metallicities, 0.0001$\leq Z \leq$0.04 and…
Measurements of the physical properties of stars at the lower end of the main sequence are scarce. In this context we report masses, radii and surface gravities of ten very-low-mass stars in eclipsing binary systems, with orbital periods of…
The NASA Kepler space telescope has detected solar-like oscillations in several hundreds of single stars, thereby providing a way to determine precise stellar parameters using asteroseismology. In this work, we aim to derive the fundamental…
We initiated long-term optical interferometry monitoring of the diameters of unstable yellow hypergiants (YHG) with the goal of detecting both the long-term evolution of their radius and shorter term formation related to large mass-loss…
Stellar feedback plays a significant role in modulating star formation, redistributing metals, and shaping the baryonic and dark structure of galaxies -- however, the efficiency of its energy deposition to the interstellar medium is…
The aim of this work was to use a multi-approach technique to derive the most accurate values possible of the physical parameters of the \delta Sct star HD174966. In addition, we searched for a periodic pattern in the frequency spectra with…
In this paper we analyse and discuss the HR Diagram position of two extra-solar planet-host stars - HD37124 and HD46375 - by means of theoretical stellar evolution models. This work was triggered by the results obtained by Laws et al.…