Zobrazeno 1 - 10
of 236
pro vyhledávání: '"Stoyanov K"'
Autor:
Stoyanov, K. A., Luna, G. J. M., Zamanov, R. K., Ilkiewicz, K., Nikolov, Y. M., Moyseev, M., Minev, M., Kurtenkov, A., Stefanov, S. Y.
T CrB is a symbiotic star that experiences nova outbursts every $\sim$ 80~yr. The next, long-anticipated nova outburst should occur during the 2024-2026 period. Here, we present results of high-resolution optical spectroscopy of T CrB in the period 2
Externí odkaz:
http://arxiv.org/abs/2406.01971
Autor:
Zamanov, R. K., Stoyanov, K. A., Marchev, V., Minev, M., Marchev, D., Moyseev, M., Marti, J., Bode, M. F., Konstantinova-Antova, R., Stefanov, S.
We present high resolution (0.06 A/px) spectroscopic observations of the recurrent nova T Coronae Borealis obtained during the last 1.5 years (September 2022 -- January 2024), with the 2.0m RCC telecope of the Rozhen National Astronomical Observatory
Externí odkaz:
http://arxiv.org/abs/2405.11506
Autor:
Zamanov, R., Stoyanov, K. A., Latev, G., Marti, J., Takey, A., Elhosseiny, E. G., Christova, M. D., Minev, M., Vujcic, V., Moyseev, M., Marchev, V.
We performed optical photometry and spectral observations of the symbiotic stars 4U1954+319 and ZZ CMi. For 4U1954+319 using high-resolution spectra we measure the equivalent widths of diffuse interstellar bands and estimate the interstellar reddenin
Externí odkaz:
http://arxiv.org/abs/2402.14378
Autor:
Nikolov, Y., Luna, G. J. M., Stoyanov, K. A., Borisov, G., Mukai, K., Sokoloski, J. L., Avramova-Boncheva, A.
Publikováno v:
A&A 679, A150 (2023)
A long-standing question related to nova eruptions is how these eruptions can lead to the formation of dust despite the ostensibly inhospitable environment for dust within the hot, irradiated ejecta. Novae in systems such as the symbiotic binary RS O
Externí odkaz:
http://arxiv.org/abs/2309.11288
We report photometry of the intranight variability of the dwarf nova RX And in two bands (B and V). The observations are carried out during three nights in November-December 2022 at the 50/70~cm Schmidt telescope of the Rozhen National Astronomical O
Externí odkaz:
http://arxiv.org/abs/2303.08616
The Be stars display variable optical emission lines originating in the circumstellar disc. Here we analyse high resolution spectroscopic observations of Be stars and the distance between the peaks of H-alpha, H-beta, and H-gamma emission lines ($\De
Externí odkaz:
http://arxiv.org/abs/2302.11975
Autor:
Tomov, N. A., Tomova, M. T., Stoyanov, K. A., Bonev, T. R., Zamanov, R. K., Iliev, I. Kh., Nikolov, Ya. M., Marchev, D., Bisikalo, D. V., Kaygorodov, P. V.
Publikováno v:
A&A 671, A49 (2023)
RS Oph is a symbiotic recurrent nova containing a massive white dwarf with heavy mass loss during activity. In August 2021, it underwent its seventh optical eruption since the end of the 19th century. The goal of this work is to analyse the structure
Externí odkaz:
http://arxiv.org/abs/2301.06643
Autor:
Zamanov, R. K., Kostov, A., Moyseev, M., Petrov, N., Nikolov, Y. M., Latev, G. Y., Marchev, D., Boeva, S., Stoyanov, K. A., Minev, M. S., Marti, J., Radeva, V., Sanchez-Ayaso, E., Bode, M. F., Ilkiewicz, K., Nikolov, G., Luque-Escamilla, P. L., Spassov, B., Borisov, B., Marchev, V. D., Kurtenkov, A.
We report photometric observations of the hidden symbiotic star SU Lyn in the optical bands. In five nights we detect a weak flickering in U band with amplitude of about 0.05 magnitudes. No intranight variations are found in B, V, g' and r' bands. Th
Externí odkaz:
http://arxiv.org/abs/2206.10151
Autor:
Zamanov, R. K., Stoyanov, K. A., Marchev, D., Tomov, N. A., Wolter, U., Bode, M. F., Nikolov, Y. M., Stefanov, S. Y., Kurtenkov, A., Latev, G. Y.
We present new spectroscopic observations of the Be/black hole binary MWC 656 obtained during the period 2015 - 2021. We measure the equivalent width of H$\alpha$ (EW$_\alpha$), H$\beta$ ($EW_\beta$), and the distance between the peaks of H$\alpha$ (
Externí odkaz:
http://arxiv.org/abs/2206.06013
Autor:
Hambaryan, V., Stoyanov, K. A., Mugrauer, M., Neuhäuser, R., Stenglein, W., Bischoff, R., Michel, K. -U., Geymeier, M., Kurtenkov, A., Kostov, A.
Based on the Gaia EDR3 astrometric parameters and our new systemic radial velocity of the high-mass X-ray binary 4U 2206+54/BD+53 2790, we studied the trace back motion of the system and propose that it originated in the subgroup of the Cepheus OB1 a
Externí odkaz:
http://arxiv.org/abs/2201.07770