相关论文: Quantitative spectroscopy of Galactic BA-type supe…

Effective temperatures of early-type supergiants are important to test stellar atmosphere- and internal structure-models of massive and intermediate mass objects at different evolutionary phases. However, these Teff values are more or less…

We describe a self-consistent spectrum analysis technique employing non-LTE line formation, which allows precise atmospheric parameters of massive stars to be derived: 1sigma-uncertainties as low as ~1% in effective temperature and…

Quantitative spectroscopy of luminous BA-type supergiants offers a high potential for modern astrophysics. The degree to which we can rely on quantitative studies of this class of stars as a whole depends on the quality of the analyses for…

Massive BA-type supergiants are among the visually brightest stars in galaxies with active star formation. As such they are versatile tools for studies of stellar and galactochemical evolution. Moreover, they can act as distance indicators…

Context. B-type supergiants are versatile tools to address various astrophysical topics, ranging from stellar atmospheres over stellar and galactic evolution to the cosmic distance scale. Aims. A hybrid non-LTE approach - line-blanketed…

Luminous BA-SGs allow topics ranging from NLTE physics and the evolution of massive stars to the chemical evolution of galaxies and cosmology to be addressed. A hybrid NLTE technique for the quantitative spectroscopy of BA-SGs is discussed.…

Blue supergiants of spectral types B and A are the visually brightest stars in spiral and irregular galaxies, with their most luminous members (at M_V=-10) outshining entire dwarf galaxies. This characteristic allows us to use them as…

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…

We performed extensive tests of the accuracy of atmospheric parameter determination for FGK stars based on the spectrum fitting procedure Spectroscopy Made Easy (SME). Our stellar sample consists of 13 objects, including the Sun, in the…

As a well-established procedure for the vast majority of normal main-sequence stars, determination of atmospheric and stellar parameters turns to be a challenging process in case of magnetic chemically peculiar stars. Inhomogeneous…

We undertake an optical and ultraviolet spectroscopic analysis of a sample of 20 Galactic B0 - B5 supergiants of luminosity classes Ia, Ib, Iab and II. Fundamental stellar parameters are obtained from optical diagnostics and a critical…

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 study the spectroscopic and photometric properties of carbon stars. In the first paper of this series we focus on objects that can be described by hydrostatic models neglecting dynamical phenomena like pulsation and mass loss. As a…

Accurate and homogeneous atmospheric parameters (Teff, log (g), Vt, [Fe/H]) are derived for 74 FGK non-variable supergiants from high-resolution, high signal-to-noise ratio, echelle spectra. Extremely high precision for the inferred…

We present a detailed analysis of 26 barium stars, including dwarf barium stars, providing their atmospheric parameters (Teff, log g, [Fe/H], vt) and elemental abundances. We aim at deriving gravities and luminosity classes of the sample…

The following parameters are determined for 63 Galactic supergiants in the solar neighbourhood: effective temperature Teff, surface gravity log g, iron abundance log e(Fe), microturbulent parameter Vt, mass M/Msun, age t and distance d. A…

Late type giants (RGB/AGB stars) will be important tracers of the Galactic morphology and evolution in the framework of Gaia, as they are intrinsically bright and thus can probe distant stellar populations or those obscured by interstellar…

In the past years we have made great efforts to reduce the statistical and systematic uncertainties in stellar parameter and chemical abundance determinations of early B-type stars. Both the construction of robust model atoms for non-LTE…

Accurate fundamental parameters of stars are mandatory for the asteroseismic investigation of the Kepler mission to succeed. We will determine the atmospheric parameters for a sample of 6 well-studied bright K giants to confirm that our…

Context: Accurate fundamental parameters of stars are essential for the asteroseismic analysis of data from the NASA Kepler mission. Aims: We aim at determining accurate atmospheric parameters and the abundance pattern for a sample of 82…