3,384 research outputs found
About the chemical composition of delta Scuti - the prototype of the class of pulsating variables
We present chemical abundances in the photosphere of Scuti -- the
prototype of the class of pulsating variables -- determined from the analysis
of a spectrum obtained at Terskol observatory 2 meter telescope with resolution
, signal to noise ratio 250. VLT and IUE spectra were used also .
Abundance pattern of \dsct consists of 49 chemical elements. The abundances of
Be, P, Ge, Nb, Mo, Ru, Er, Tb, Dy, Tm, Yb, Lu, Hf, Ta, Os, Pt, Th were not
investigated previously. The lines of third spectra of Pr and Nd also are
investigated for the first time. The abundances of heavy elements show the
overabundances with respect to the Sun up to 1 dex. The abundance pattern of
\dsct is similar to that of Am-Fm stars.Comment: 8 pages, 2 figures, subm. to Proc. of IAU Symp. 22
Some Statistical Picture of Magnetic CP Stars Evolution
We discuss some statistical results on the evolution of magnetic CP stars in
the framework of the supposition about their binary nature.Comment: 3 pages, 3 figure
The chemical composition of a mild barium star HD202109
We present the result of chemical abundances of a mild barium star HD202109
(zeta Cyg) determined from the analysis of spectrum obtained by using a 2-m
telescope at the Peak Terskol Observatory and a high-resolution spectrometer
with R=80,000, signal to noise ratio >100. We also present the atmospheric
parameters of the star determined by using various methods including iron-line
abundance analysis. For line identifications, we use whole-range synthetic
spectra computed by using the Kurucz database and the latest lists of spectral
lines. Among the determined abundances of 51 elements, those of P, S, K, Cu,
Zn, Ge, Rb, Sr, Nb, Mo, Ru, Rh, Pd, In, Sm, Gd, Tb, Dy, Er, Tm, Hf, Os, Ir, Pt,
Tl, and Pb have not been previously known. Under the assumption that the
overabundance pattern of Ba stars is due to wind-accretion process, adding
information of more element abundances enables one to show that the heavy
element overabundances of HD202109 can be explained with the wind accretion
scenario model.Comment: 10 pages, Accepted by Astronomy and Astrophysic
Investigation of nanoporous material under quasi-equilibrium conditions
Based on the three parametric Lorenz system, a model was developed that
permits to describe the behavior of the plasma-condensate system near phase
equilibrium in a self-consistent way. Considering the effect of fluctuations of
the growth surface temperature, the evolution equation and the corresponding
Fokker-Planck equation were obtained. The phase diagram is built which
determines the system parameters corresponding to the regime of the porous
structure formation.Comment: 8 pages, 3 figure
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