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Information × Registration Number 0215U001077, 0109U008358 , R & D reports Title Features of chemical abundances of stellar atmospheres at different stages of evolution and physics of the ultracool dwarfs of Galaxy popup.stage_title Head Pavllenko Ya.V., Registration Date 16-01-2015 Organization Main Astronomical Observatory popup.description2 Spectra modelling of ultracool dwarfs set was carried out. Physical parameters of these stars were specified and it was shown they belongs to definite moving stellar clusters. Two brown dwarfs were discovered. NIR spectra of field cool dwarfs were modelled, basic physical characteristics and rotational velocities were determined. Element abundances of some chemical elements were determined using self-consistent technique, which is useful for their nature and evolution status detecting. Absorption lines formation analysis, especially strong H and K Ca II, in 1D and MHD stellar model atmospheres show their dependence on size of inhomogeneities in stellar atmospheres. Physical characteristics analysis of F-G supergiants was carried out. The lithium abundances in the atmospheres of these stars were determined. Complex analysis of RS Oph was performed. $^{12}$C/$^{13}$C~ in the atmosphere of the red giant and the features of the dusty envelope of the system were determined. Distribution of the definite chemical elements on surfaces of chemically peculiar stars with magnetic fields and vertical stratification of these elements were determined. Doppler Image Analysis of line profiles show the equivalence of magnetic characteristics of HD 12098 and HD 60435 stars, which is similar to other Ap stars. Basic physical characteristics of number of carbon peculiar giants, including R CrB stars, were determined. The lithium abundance for some N-J giants was detected. Product Description popup.authors Камінський Б.М. Ковальчук Г.У. Любчик Ю.П. Михайлицька Н. Павленко Я.В. Шаврина А.В. Шемінова В.А. Яковіна Л.Я. popup.nrat_date 2020-04-02 Close