902 citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- Bulgarian Academy of SciencesBG224 papers
- Centre National de la Recherche ScientifiqueFR67 papers
- Sofia University "St. Kliment Ohridski"BG64 papers
- Shumen UniversityBG62 papers
- Instituto de Astrofísica de CanariasES57 papers
- Instituto de Astrofísica de AndalucíaES55 papers
- National Institute for AstrophysicsIT54 papers
- Universidad de La LagunaES50 papers
- Astronomical ObservatoryRS48 papers
- Evgeni Kharadze Georgian National Astrophysical ObservatoryGE45 papers
- Aryabhatta Research Institute of Observational SciencesIN43 papers
- Osservatorio Astrofisico di TorinoIT43 papers
205 papers · 1 filter
Data-driven segmentation of solar filaments based on ground-based instrument data
Oleg Stepanyuk, Werner Pötzi, Momchil Dechev +2
The dynamic behavior of solar prominences and filaments is a precursor to coronal mass ejections (CMEs), which can disrupt Earth's magnetosphere and affect satellite communications…
Polarimetric and spectropolarimetric observations with FoReRo2: Instrument overview and standard star monitoring
Yanko Nikolov, Galin Borisov, Stefano Bagnulo +3
In this paper, we present a description and characterisation of the 2-Channel Focal Reducer Rozhen (FoReRo2), with an emphasis on its polarimetric and spectropolarimetric observati…
Multi-Instrument Observations and Tracking of a Coronal Mass Ejection Front From Low to Middle Corona
Oleg Stepanyuk, Kamen Kozarev
The shape and dynamics of coronal mass ejections (CMEs) vary significantly based on the instrument and wavelength used. This has led to significant debate about the proper definiti…
Type II radio bursts and space weather phenomena: A statistical study
Pooja Devi, Rositsa Miteva, Ramesh Chandra +2
In this paper, we present for the first time a comprehensive statistical study between type II radio bursts from the metric (m) to the dekameric-hectometric (DH) domain and their a…
Source location and evolution of a multi-lane type II radio burst
P. Zucca, P. Zhang, K. Kozarev +8
Shocks in the solar corona can accelerate electrons that in turn generate radio emission known as type II radio bursts. The characteristics and morphology of these radio bursts in…
Investigation of the Nature of the B[e] Star CI Cam in the Optical Range
E. A. Barsukova, A. N. Burenkov, V. P. Goranskij +10
We report the results of 24 years of photometric and spectroscopic monitoring of CI Cam since its outburst in 1998. In the early years of our research, we identified a system compo…
4D Grid-fitting of UV-optical spectra of massive stars. I. Numerical technique and its associated uncertainties
Blagovest V. Petrov, Svetozar A. Zhekov
The best way to check the validity of our theories (models) is by direct comparison with the experiment (observations). In this study, we address the numerical inaccuracies intrins…
S-Process Nucleosynthesis in Chemically Peculiar Binaries
A. J. Dimoff, C. J. Hansen, R. J. Stancliffe +4
Around half of the heavy elements in the universe are formed through the slow neutron capture (s-) process, which takes place in thermally pulsing asymptotic giant branch (AGB) sta…
A new dimension in the variability of AGB stars: convection patterns size changes with pulsation
A. Rosales-Guzmán, J. Sanchez-Bermudez, C. Paladini +16
Stellar convection plays an important role in atmospheric dynamics, wind formation and the mass-loss processes in Asymptotic Giant Branch (AGB) stars. However, a direct characteriz…
Tracking the motion of a shock along a channel in the low solar corona
J. Rigney, P. T. Gallagher, G. Ramsay +4
Shock waves are excited by coronal mass ejections (CMEs) and large-scale extreme-ultraviolet (EUV) wave fronts and can result in low-frequency radio emission under certain coronal…
Forecasting Solar Energetic Proton Integral Fluxes with Bi-Directional Long Short-Term Memory Neural Networks
Mohamed Nedal, Kamen Kozarev, Nestor Arsenov +1
Solar energetic particles are mainly protons and originate from the Sun during solar flares or coronal shock waves. Forecasting the Solar Energetic Protons (SEP) flux is critical f…
Transient and asymmetric dust structures in the TeV-bright nova RS Oph revealed by spectropolarimetry
Y. Nikolov, G. J. M. Luna, K. A. Stoyanov +4
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,…
Symbiotic star T CrB as an extreme SU UMa type dwarf nova
Krystian Ilkiewicz, Joanna Mikolajewska, Kiril A. Stoyanov
T CrB is a symbiotic recurrent nova that exhibits quiescent and active phases between its classical nova eruptions. The statistical properties of these active phases have been poor…
Study of the long-term photometric variability of eight PMS stars in the young open cluster Trumpler 37
Sunay Ibryamov, Gabriela Zidarova, Evgeni Semkov +1
This paper reports results from our long-term photometric CCD observations of eight pre-main-sequence stars collected from June 2008 to October 2022. These stars are l…
Surface magnetism in the pulsating RV Tauri star R Scuti
Stefan Georgiev, Agnès Lèbre, Eric Josselin +3
We present the surface magnetic field conditions of the brightest pulsating RV Tauri star, R Sct. Our investigation is based on the longest spectropolarimetric survey ever performe…
Assessing the spectral characteristics of band splitting type II radio bursts observed by CALLISTO spectrometers
F. N. Minta, S. Nozawa, K. Kozarev +2
Metric type II radio bursts are usually early indicators of CME-driven shocks and other space weather phenomena in the solar corona. This paper presents a detailed investigation of…
Optical spectroscopy of Be stars: peak separation of Balmer emission lines
R. K. Zamanov, K. A. Stoyanov, S. Y. Stefanov +2
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…
RFI Flagging in Solar and Space Weather Low Frequency Radio Observations
Peijin Zhang, André R. Offringa, Pietro Zucca +2
Radio spectroscopy provides a unique inspection perspective for solar and space weather research, which can reveal the plasma and energetic electron information in the solar corona…
Solar radio bursts observations by Egypt- Alexandria CALLISTO spectrometer: First results
F. N. Minta, S. Nozawa, K. Kozarev +2
The newly installed CALLISTO spectrometer, hosted by the Department of Space Environment, Institute of Basic and Applied Sciences- EJUST, commenced operation on August 14, 2021. Th…
Tilted discs in six poorly studied cataclysmic variables
Stefan Y. Stefanov, Atanas K. Stefanov
In this work, we search for negative superhumps (nSHs) in poorly studied cataclysmic variables using TESS data. We find three eclipsing binaries with nSH signatures: HBHA 4204-09,…
Mass outflow from the symbiotic binary RS Oph during its 2021 outburst
N. A. Tomov, M. T. Tomova, K. A. Stoyanov +7
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…
The height of convective plumes in the red supergiant Cep
A. López Ariste, M. Wavasseur, Ph. Mathias +3
Aims. We seek to understand convection in red supergiants and the mechanisms that trigger the mass loss from cool evolved stars. Methods. Linear spectropolarimetry of the atomic li…
Recent humps and superhumps observations and an estimation of outburst parameters of the AM CVn star CR Boo
Daniela Boneva, Radoslav Zamanov, Svetlana Boeva +4
We present our observational results of AM CVn star CR Boo in the UBVR bands. Our observational campaign includes data obtained over 5 nights with the National Astronomical Observa…
For optical flickering in symbiotic star MWC 560
Dragomir Marchev, Kiril Stoyanov, Vladislav Marchev +5
This study is based on observations of MWC560 during the last two observational seasons (2020/2021 and 2021/2022). Other than looking for flickering we were interested in following…