Search Results - "Ryabchikova, T"

A non-local thermodynamical equilibrium line formation for neutral and singly ionized titanium in model atmospheres of reference A–K stars by Sitnova, T. M., Mashonkina, L. I., Ryabchikova, T. A.

“…We construct a model atom for Ti i–ii using more than 3600 measured and predicted energy levels of Ti i and 1800 energy levels of Ti ii, and quantum mechanical…”
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BD +30°549: a young helium-weak silicon star in the NGC 1333 star-forming region by Potravnov, I, Mashonkina, L, Ryabchikova, T

“…ABSTRACT We present results of the spectroscopic study of the chemically peculiar star BD +30°549, which is a bona fide member of the young NGC 1333…”
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Detailed abundances of the wide pairs of stars with and without planets: the binary systems 16 Cyg and HD 219542 by Ryabchikova, T, Pakhomov, Yu, Mashonkina, L, Sitnova, T

“…ABSTRACT We present results of the comparative analysis of the two wide binary systems – 16 Cyg, with a giant gas planet orbiting around 16 Cyg B, and…”
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A major upgrade of the VALD database by Ryabchikova, T, Piskunov, N, Kurucz, R L, Stempels, H C, Heiter, U, Pakhomov, Yu, Barklem, P S

“…Vienna atomic line database (VALD) is a collection of critically evaluated laboratory parameters for individual atomic transitions, complemented by theoretical…”
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Chemical diversity among A–B stars with low rotational velocities: non-LTE abundance analysis by Mashonkina, L, Ryabchikova, T, Alexeeva, S, Sitnova, T, Zatsarinny, O

“…ABSTRACT We present accurate element abundance patterns based on the non-local thermodynamic equilibrium (non-LTE, NLTE) line formation for 14 chemical…”
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Accuracy of atmospheric parameters of FGK dwarfs determined by spectrum fitting by Ryabchikova, T., Piskunov, N., Pakhomov, Yu, Tsymbal, V., Titarenko, A., Sitnova, T., Alexeeva, S., Fossati, L., Mashonkina, L.

“…We performed extensive tests of the accuracy of atmospheric parameter determination for FGK stars based on the spectrum fitting procedure Spectroscopy Made…”
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A NLTE line formation for neutral and singly ionized calcium in model atmospheres of B-F stars by Sitnova, T M, Mashonkina, L I, Ryabchikova, T A

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Putting atomic diffusion theory of magnetic ApBp stars to the test: evaluation of the predictions of time-dependent diffusion models by Kochukhov, O, Ryabchikova, T A

“…Abstract A series of recent theoretical atomic diffusion studies has address the challenging problem of predicting inhomogeneous vertical and horizontal…”
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Doppler imaging of a southern ApSi star HD 152564 by Potravnov, I, Ryabchikova, T, Piskunov, N, Pakhomov, Y, Kniazev, A

“…ABSTRACT We present the results of the spectroscopic study of a chemically peculiar star HD 152564. Using medium-resolution (R = 37 000) observations obtained…”
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NLTE carbon abundance determination in selected A- and B-type stars and the interpretation of C i emission lines by Alexeeva, S. A., Ryabchikova, T. A., Mashonkina, L. I.

“…We constructed a comprehensive model atom for C i–C ii using the most up-to-date atomic data available and evaluated the non-local thermodynamic equilibrium…”
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Non-LTE Nitrogen Abundances in the Sun and Selected A–F-Type Stars by Mashonkina, L. I., Ryabchikova, T. A.

“…A new N I model atom has been constructed using the energy levels known from laboratory measurements and predicted in N I atomic structure calculations and…”
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Non-LTE abundance analysis of A-B stars with low rotational velocities – II. Do A-B stars with normal abundances exist? by Romanovskaya, A M, Ryabchikova, T A, Pakhomov, Yu V, Korotin, S A, Sitnova, T M

“…ABSTRACT We present chemical composition and fundamental parameters (the effective temperature, surface gravity, and radius) for four sharp-lined A-type stars…”
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Fundamental parameters and evolutionary status of the magnetic chemically peculiar stars HD 188041 (V1291 Aquilae), HD 111133 (EP Virginis), and HD 204411: spectroscopy versus interferometry by Romanovskaya, A, Ryabchikova, T, Shulyak, D, Perraut, K, Valyavin, G, Burlakova, T, Galazutdinov, G

“…ABSTRACT The determination of fundamental parameters of stars is one of the main tasks of astrophysics. For magnetic chemically peculiar stars, this problem is…”
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Hyperfine Splitting in the VALD Database of Spectral-line Parameters by Pakhomov, Yu. V., Ryabchikova, T. A., Piskunov, N. E.

“…The Vienna Atomic Line Database (VALD) has been supplemented with new data and new functionality—the possibility of taking into account the effect of hyperfine…”
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Fundamental parameters and abundance analysis of the components in the SB2 system HD 60803 by Ryabchikova, T, Zvyagintsev, S, Tkachenko, A, Tsymbal, V, Pakhomov, Yu, Semenko, E

“…ABSTRACT We perform a detailed spectroscopic study of the SB2 system HD 60803 based on high-resolution spectra obtained with different spectrographs. The…”
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Evaluation of the Recent Atomic Data for Fe i Lines Based on Solar and Stellar Spectra by Ryabchikova, T., Piskunov, N., Sitnova, T.

“…We performed an extensive comparative analysis of the recent experimental data on Fe  i transition probabilities (TP) based on the observed solar and stellar…”
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V772 Cas: an ellipsoidal HgMn star in an eclipsing binary by Kochukhov, O, Johnston, C, Labadie-Bartz, J, Shetye, S, Ryabchikova, T A, Tkachenko, A, Shultz, M E

“…ABSTRACT The late B-type star V772 Cas (HD 10260) was previously suspected to be a rare example of a magnetic chemically peculiar star in an eclipsing binary…”
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Investigation of the dependence of rare-earth element abundances on the effective temperature and magnetic field in the atmospheres of chemically peculiar (Ap) stars by Ryabchikova, T. A., Romanovskaya, A. M.

“…We have derived the abundances of the rare-earth elements (REEs) Ce, Pr, Nd, and Eu in the atmospheres of 26 magnetic peculiar (Ap) stars in the range of…”
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TYC 8606-2025-1: a mild barium star surrounded by the ejecta of a very late thermal pulse by Gvaramadze, V V, Pakhomov, Yu V, Kniazev, A Y, Ryabchikova, T A, Langer, N, Fossati, L, Grebel, E K

“…ABSTRACT We report the discovery of a spiral-like nebula with the Wide-field Infrared Survey Explorer and the results of optical spectroscopy of its associated…”
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Echography of young stars reveals their evolution by Zwintz, K., Fossati, L., Ryabchikova, T., Guenther, D., Aerts, C., Barnes, T. G., Themeßl, N., Lorenz, D., Cameron, C., Kuschnig, R., Pollack-Drs, S., Moravveji, E., Baglin, A., Matthews, J. M., Moffat, A. F. J., Poretti, E., Rainer, M., Rucinski, S. M., Sasselov, D., Weiss, W. W.

“…We demonstrate that a seismic analysis of stars in their earliest evolutionary phases is a powerful method with which to identify young stars and distinguish…”
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