Physica Scripta Volume T, 133, p. 4010, http://dx.doi.org./10.1088/0031-8949//t133/014010
This paper presents the results of a detailed investigation of the validity of oscillator strengths in the spectral domain of the Gaia spectrometer 848-875 nm. This analysis is performed by fitting the most significant Fe I and Si I solar lines in this spectral range with synthetic profiles calculated by 3D radiative hydrodynamical (RHD)...
Context: Thanks to its proximity, alpha Centauri is an outstanding target for an imaging search for extrasolar planets. Aims: We searched for faint comoving companions to alpha Cen located at angular distances of a few tens of arcseconds, up to 2-3 arcmin. Methods: We obtained CCD images from the NTT-SUSI2 instrument in the Bessel V, R, I, and...
Journal of Physics Conference Series, 130, p. 2001, http://dx.doi.org./10.1088/1742-6596/130/1/012001
HD 179821 is classified as G5 Ia star. From the IRAS colors and spectral energy distributions it was classified as a post-AGB star. But some studies classify it as a massive (30 to 19 M sun) post-red supergiant evolving to become a Type II supernova. Its mass and evolutionary status remained a hotly debated question even after several detailed...
The effects of background line opacity (line-blocking) in statistical equilibrium calculations for Fe in late-type stellar atmospheres have been investigated using an extensive and up-to-date model atom with radiative data primarily from the Project. The background metal line opacities have been computed using data from the stellar...
For the nearby dwarf star α Cen B (K1 V), we present limb-darkening predictions from a 3D hydrodynamical radiative transfer model of its atmosphere. We first compared the results of this model to a standard Kurucz's atmosphere. Then we used both predictions to fit the new interferometric visibility measurements of α Cen B obtained with the...
For the nearby dwarf star α Cen B (K1 V), we present limb-darkening predictions from a 3D hydrodynamical radiative transfer model of its atmosphere. We first compared the results of this model to a standard Kurucz's atmosphere. Then we used both predictions to fit the new interferometric visibility measurements of α Cen B obtained with the...
Astronomy and Astrophysics, 493, pp. 107-114, http://dx.doi.org./10.1051/0004-6361:200810565
Context. Recently the triple-α reaction rate has been re-evaluated. In the temperature range, 107-108 K, with respect to the NACRE rate, the new rate is enhanced by up to 20 orders-magnitude. Aims: To validate this new rate, we investigate its consequences for the evolution of Cepheid models. Methods: The stellar evolutionary tracks are...