Search Results - "Stoyanov, K. A."

Rotational velocities of the giants in symbiotic stars – III. Evidence of fast rotation in S-type symbiotics by Zamanov, R. K., Bode, M. F., Melo, C. H. F., Stateva, I. K., Bachev, R., Gomboc, A., Konstantinova-Antova, R., Stoyanov, K. A.

“…We have measured the projected rotational velocities (v sin i) in a number of symbiotic stars and M giants using high-resolution spectroscopic observations. On…”
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Orbital parameters of the high-mass X-ray binary 4U 2206+54 by Stoyanov, K. A., Zamanov, R. K., Latev, G. Y., Abedin, A. Y., Tomov, N. A.

“…We present new radial velocities of the high‐mass X‐ray binary star 4U 2206+54 based on optical spectra obtained with the Coudé spectrograph at the 2 m RCC…”
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Difference between the optical flickering colours of cataclysmic variables and symbiotic recurrent novae by Zamanov, R., Boeva, S., Latev, G., Stoyanov, K. A., Tsvetkova, S. V.

“…We performed simultaneous observations in 3 bands (U BV) of the flickering variability of the recurrent novae RS Oph and T CrB at quiescence. Using new and…”
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AG Pegasi – now a classical symbiotic star in outburst? by Tomov, T. V., Stoyanov, K. A., Zamanov, R. K.

“…Optical spectroscopy study of the recent AG Pegasi (AG Peg) outburst observed during the second half of 2015 is presented. Considerable variations of the…”
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UBVRI observations of the flickering of RS Ophiuchi at quiescence by Zamanov, R. K., Boeva, S., Bachev, R., Bode, M. F., Dimitrov, D., Stoyanov, K. A., Gomboc, A., Tsvetkova, S. V., Slavcheva-Mihova, L., Spasov, B., Koleva, K., Mihov, B.

“…We report observations of the flickering variability of the recurrent nova RS Oph at quiescence on the basis of simultaneous observations in five bands…”
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The origin of the high-mass X-ray binary 4U 2206+54/BD+532790 by Hambaryan, V, Stoyanov, K A, Mugrauer, M, Neuhäuser, R, Stenglein, W, Bischoff, R, Michel, K-U, Geymeier, M, Kurtenkov, A, Kostov, A

“…ABSTRACT Based on the Gaia EDR3 astrometric parameters and our new systemic radial velocity of the high-mass X-ray binary 4U 2206+54/BD+532790, we studied the…”
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An eccentric wave in the circumstellar disc of the Be/X-ray binary X Persei by Zamanov, R K, Stoyanov, K A, Wolter, U, Marchev, D, Tomov, N A, Bode, M F, Nikolov, Y M, Marchev, V, Iliev, L, Stateva, I K

“…ABSTRACT We present spectroscopic observations of the Be/X-ray binary X Per obtained during the period 2017 December–2020 January (MJD 58095–58865). In 2017…”
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Size of the accretion disc in the recurrent nova T CrB by Zamanov, R. K., Stoyanov, K. A., Marchev, V., Minev, M., Marchev, D., Moyseev, M., Martí, J., Bode, M. F., Konstantinova‐Antova, R., Stefanov, S.

“…Abstract We present high‐resolution (0.06 Å px) spectroscopic observations of the recurrent nova T Coronae Borealis obtained during the last 1.5 years…”
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Optical Spectroscopy and X-Ray Observations of the D-Type Symbiotic Star EF Aql by Stoyanov, K A, lkiewicz, K I, Luna, G J M, lajewska, J Miko, Mukai, K, Marti, J, Latev, G, Boeva, S, Zamanov, R K

“…We performed high-resolution optical spectroscopy and X-ray observations of the recently identified Mira-type symbiotic star EF Aql. Based on high-resolution…”
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Flickering of the jet‐ejecting symbiotic star MWC 560 by Zamanov, R. K., Boeva, S., Stoyanov, K. A., Latev, G., Spassov, B., Kurtenkov, A., Nikolov, G.

“…We analyzed the optical photometric data of short‐term variability (flickering) of the accreting white dwarf in the jet‐ejecting symbiotic star MWC 560. The…”
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Flickering of accreting white dwarfs: the remarkable amplitude–flux relation and disc viscosity by Zamanov, R. K., Boeva, S., Latev,  G., Sokoloski, J. L., Stoyanov,  K. A., Genkov, V., Tsvetkova, S. V., Tomov, T., Antov, A., Bode, M. F.

“…We analyse optical photometric data of short term variability (flickering) of accreting white dwarfs in cataclysmic variables (KR Aur, MV Lyr, V794 Aql, TT…”
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Discovery of optical flickering from the symbiotic star EF Aquilae by Zamanov, R. K., Boeva, S., Nikolov, Y. M., Petrov, B., Bachev, R., Latev, G. Y., Popov, V. A., Stoyanov, K. A., Bode, M. F., Martí, J., Tomov, T., Antonova, A.

“…We report optical charge‐coupled device (CCD) photometry of the recently identified symbiotic star EF Aquilae (EF Aql). Our observations in the Johnson V and B…”
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The cataclysmic variable AE Aquarii: B–V color of the flares by Zamanov, R. K., Latev, G. Y., Boeva, S., Ibryamov, S., Nikolov, G. B., Stoyanov, K. A.

“…We report simultaneous observations of the flaring behavior of the cataclysmic variable star AE Aquarii (AE Aqr). The observations are in Johnson B and V…”
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AG Pegasi – now a classical symbiotic star in outburst? by Tomov, T. V., Stoyanov, K. A., Zamanov, R. K.

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Transient and asymmetric dust structures in the TeV-bright nova RS Oph revealed by spectropolarimetry by Nikolov, Y, Luna, G. J. M, Stoyanov, K. A, Borisov, G, Mukai, K, Sokoloski, J. L, Avramova-Boncheva, A

“…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…”
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Optical spectroscopy of Be stars: peak separation of Balmer emission lines by Zamanov, R. K, Stoyanov, K. A, Stefanov, S. Y, Bode, M. F, Minev, M. S

“…The Be stars display variable optical emission lines originating in the circumstellar disc. Here we analyse high resolution spectroscopic observations of Be…”
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The origin of the high-mass X-ray binary 4U 2206+54/BD +53 2790 by 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…”
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DSC study of thermal decomposition of partially ozonized diene rubbers by Anachkov, M. P., Rakovski, S. K., Stoyanov, A. K.

“…The thermal decompositions of partially ozonized 1,4‐cis‐polybutadiene (E‐BR), 1,4‐cis‐polyisoprene (E‐IR), 1,4‐trans‐polyisoprene (Z‐IR),…”
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Simultaneous UBVRI observations of the cataclysmic variable AE Aquarii: Temperatures and masses of fireballs by Zamanov, R.K., Latev, G.Y., Stoyanov, K.A., Boeva, S., Spassov, B., Tsvetkov, S.V.

“…We report simultaneous multicolour observations in 5 bands (UBVRI) of the flickering variability of the cataclysmic variable AE Aqr. Our aim is to estimate the…”
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Mass outflow from the symbiotic binary RS Oph during its 2021 outburst by 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

“…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…”
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