Zobrazeno 1 - 10
of 329
pro vyhledávání: '"Kovtyukh, V."'
The purpose of this work is to spectroscopically analyse the classical Cepheid V708 Car. A preliminary check of the spectrum of V708 Car showed that this is a lithium-rich supergiant. We also found that V708 Car has an unusual chemical composition in
Externí odkaz:
http://arxiv.org/abs/2402.13072
While looking for recently discovered distant Cepheids with an interesting chemical composition, we noticed one star (OGLE GD-CEP-1353) with extremely large equivalent widths of spectral lines of heavy elements. The aim of this work is to perform an
Externí odkaz:
http://arxiv.org/abs/2310.10381
Autor:
da Silva, R., D'Orazi, V., Palla, M., Bono, G., Braga, V. F., Fabrizio, M., Lemasle, B., Spitoni, E., Matteucci, F., Jonsson, H., Kovtyukh, V., Magrini, L., Bergemann, M., Dall'Ora, M., Ferraro, I., Fiorentino, G., Francois, P., Iannicola, G., Inno, L., Kudritzki, R. -P., Matsunaga, N., Monelli, M., Nonino, M., Sneden, C., Storm, J., Thevenin, F., Tsujimoto, T., Zocchi, A.
Publikováno v:
A&A 678, A195 (2023)
Classical Cepheids (CCs) are solid distance indicators and tracers of young stellar populations. Our aim is to provide iron, oxygen, and sulfur abundances for the largest and most homogeneous sample of Galactic CCs ever analyzed. The current sample c
Externí odkaz:
http://arxiv.org/abs/2308.01928
Autor:
Kovtyukh, V., Lemasle, B., Nardetto, N., Bono, G., da Silva, R., Matsunaga, N., Yushchenko, A., Fukue, K., Grebel, E. K.
The technique of line depth ratios (LDR) is one of the methods to determine the effective temperature of a star. They are crucial in the spectroscopic studies of variable stars like Cepheids since no simultaneous photometry is usually available. A go
Externí odkaz:
http://arxiv.org/abs/2307.00341
Autor:
Lemasle, B., Lala, H. N., Kovtyukh, V., Hanke, M., Prudil, Z., Bono, G., Braga, V. F., da Silva, R., Fabrizio, M., Fiorentino, G., Francois, P., Grebel, E. K., Kniazev, A.
Publikováno v:
A&A 668, A40 (2022)
Mapping the Galactic spiral structure is a difficult task since the Sun is located in the Galactic plane and because of dust extinction. For these reasons, molecular masers in radio wavelengths have been used with great success to trace the Milky Way
Externí odkaz:
http://arxiv.org/abs/2209.02731
Autor:
da Silva, R., Crestani, J., Bono, G., Braga, V. F., D'Orazi, V., Lemasle, B., Bergemann, M., Dall'Ora, M., Fiorentino, G., François, P., Groenewegen, M. A. T., Inno, L., Kovtyukh, V., Kudritzki, R. -P., Matsunaga, N., Monelli, M., Pietrinferni, A., Porcelli, L., Storm, J., Tantalo, M., Thévénin, F.
Publikováno v:
A&A 661, A104 (2022)
Classical Cepheids are the most popular distance indicators and tracers of young stellar populations. The key advantage is that they are bright and they can be easily identified in Local Group and Local Volume galaxies. Their evolutionary and pulsati
Externí odkaz:
http://arxiv.org/abs/2202.07945
Autor:
Kovtyukh, V., Lemasle, B., Bono, G., Usenko, I. A., da Silva, R., Kniazev, A., Grebel, E. K., Andronov, I. L., Shakun, L., Chinarova, L.
Radial abundance gradients provide sound constraints for chemo-dynamical models of galaxies. Azimuthal variations of abundance ratios are solid diagnostics to understand their chemical enrichment. In this paper we investigate azimuthal variations of
Externí odkaz:
http://arxiv.org/abs/2112.04258
Stellar parameters of 25 planet-hosting stars and abundances of Li, C, O, Na, Mg, Al, S, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Ni, Zn, Y, Zr, Ba, Ce, Pr, Nd, Sm and Eu, were studied based on homogeneous high resolution spectra and uniform techniques. The ir
Externí odkaz:
http://arxiv.org/abs/2104.10894
Autor:
Bono, G., Braga, V. F., Crestani, J., Fabrizio, M., Sneden, C., Marconi, M., Preston, G. W., Mullen, J. P., Gilligan, C. K., Fiorentino, G., Pietrinferni, A., Altavilla, G., Buonanno, R., Chaboyer, B., da Silva, R., Dall'Ora, M., Degl'Innocenti, S., Di Carlo, E., Ferraro, I., Grebel, E., Iannicola, G., Inno, L., Kovtyukh, V., Kunder, A., Lemasle, B., Marengo, M., Marinoni, S., Marrese, P. M., Martínez-Vázquez, C. E., Matsunaga, N., Monelli, M., Neeley, J., Nonino, M., Moroni, P. G. Prada, Prudil, Z., Stetson, P. B., Thévenin, F., Tognelli, E., Valenti, E., Walker, A. R.
We collected over 6000 high-resolution spectra of four dozen field RR Lyrae (RRL) variables pulsating either in the fundamental (39 RRab) or in the first overtone (9 RRc) mode. We measured radial velocities (RVs) of four strong metallic and four Balm
Externí odkaz:
http://arxiv.org/abs/2005.11566
Autor:
Kovtyukh, V. V., Andrievsky, S. M., Martin, R. P., Korotin, S. A., Lepine, J. R. D., Maciel, W. J., , L. E Keir, Panko, E. A.
We have made the first attempt to derive the chemical properties of the Galactic disc at its very central part using high-resolution infrared spectroscopic observations of four classical Cepheids. Those stars are located at Galactocentric distances s
Externí odkaz:
http://arxiv.org/abs/1909.00662