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
20 papers · 1 filter
The FUor star V2493 Cyg (HBC 722) -- eleven years at maximum brightness
Evgeni Semkov, Sunay Ibryamov, Stoyanka Peneva
At the time of stellar evolution, young stellar objects go through processes of increased activity and instability. Star formation takes place in several stages during which the st…
SU Lyn -- a transient symbiotic star
Krystian Ilkiewicz, Joanna Mikolajewska, Simone Scaringi +3
SU Lyn is a binary system composed of a white dwarf and a red giant star. Although it is known to be bright and variable at X-ray wavelengths, the optical counterpart of the source…
Chandra revisits WR48a: testing colliding wind models in massive binaries
Svetozar A. Zhekov, Marc Gagne, Stephen L. Skinner
We present results of new Chandra High-Energy Transmission Grating (HETG) observations (2019 November - December) of the massive Wolf-Rayet (WR) binary WR 48a. Analysis of these hi…
Toward Improved Understanding of Magnetic Fields Participating in Solar Flares: Statistical Analysis of Magnetic Field within Flare Ribbons
Maria D. Kazachenko, Benjamin J. Lynch, Antonia Savcheva +2
Violent solar flares and coronal mass ejections (CMEs) are magnetic phenomena. However, how magnetic fields reconnecting in the flare differ from non-flaring magnetic fields remain…
Revisiting TrES-5 b: departure from a linear ephemeris instead of short-period transit timing variation
G. Maciejewski, M. Fernandez, F. Aceituno +4
The orbital motion of the transiting hot Jupiter TrES-5 b was reported to be perturbed by a planetary companion on a nearby orbit. Such compact systems do not frequently occur in n…
Rotation acceleration of asteroids (10115) 1992 SK, (1685) Toro, and (1620) Geographos due to the YORP effect
J. Durech, D. Vokrouhlicky, P. Pravec +28
The rotation state of small asteroids is affected by the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect, which is a net torque caused by solar radiation directly reflected and…
Time evolution of magnetic activity cycles in young suns: The curious case of kappa Ceti
S. Boro Saikia, T. Lueftinger, C. P. Folsom +15
A detailed investigation of the magnetic properties of young Sun-like stars can provide valuable information on our Sun's magnetic past and its impact on the early Earth. We determ…
The symbiotic binary St 2-22: Orbital and stellar parameters and jet evolution following its 2019 outburst
Cezary Galan, Joanna Mikolajewska, Krystian Ilkiewicz +3
St 2-22 is a relatively poorly studied S-type symbiotic system that belongs to a small group of jet-producing systems as a result of disc accretion onto a white dwarf fed by its re…
Periodic variability of the z=2.0 quasar QSO B1312+7837
M. Minev, V. D. Ivanov, T. Trifonov +6
We report here the first results from a 15-yr long variability monitoring of the z=2.0 quasar QSO B1312+7837. It shows luminosity changes with a period P~6.13 yr (P~2.04 yr at rest…
Spectral Evolution of the X-Ray Remnant of SN 1987A: A High-Resolution HETG Study
Aravind P. Ravi, Sangwook Park, Svetozar A. Zhekov +4
Based on observations with the X-ray Observatory, we present the latest spectral evolution of the X-ray remnant of SN 1987A (SNR 1987A). We present a high-resolution spec…
Mid-Cycle Observations of CR Boo and Estimation of the System's Parameters
Daniela Boneva, Svetlana Boeva, Yanko Nikolov +2
We present observations (with NAO Rozhen and AS Vidojevica telescopes) of the AM Canum Venaticorum (AM CVn) type binary star CR Bootis (CR Boo) in the UBV bands. The data were obta…
Extraction of a second power-law tail of the density distribution in simulated clouds
L. Marinkova, T. Veltchev, Ph. Girichidis +1
The emergence and development of a power-law tail (PLT) at the high-density end of the observed column-density distribution is thought to be indicative for advanced evolution of st…
Investigation of the correlation patterns and the Compton dominance variability of Mrk 421 in 2017
MAGIC Collaboration, V. A. Acciari, S. Ansoldi +284
We present a detailed characterisation and theoretical interpretation of the broadband emission of the paradigmatic TeV blazar Mrk 421, with special focus on the multi-band flux co…
TESS Cycle 1 observations of roAp stars with 2-min cadence data
D. L. Holdsworth, M. S. Cunha, D. W. Kurtz +41
We present the results of a systematic search for new rapidly oscillating Ap (roAp) stars using the 2-min cadence data collected by the Transiting Exoplanet Survey Satellite (TESS)…
The complex variability of blazars: Time-scales and periodicity analysis in S4 0954+65
C. M. Raiteri, M. Villata, V. M. Larionov +3
Among active galactic nuclei, blazars show extreme variability properties. We here investigate the case of the BL Lac object S4 0954+65 with data acquired in 2019-2020 by the Trans…
(6478) Gault: Physical characterization of an active main-belt asteroid
Maxime Devogèle, Marin Ferrais, Emmanuel Jehin +22
In December 2018, the main-belt asteroid (6478)~Gault was reported to display activity. Gault is an asteroid belonging to the Phocaea dynamical family and was not previously known…
Long-term CCD photometry of pre-main-sequence stars in the association Cepheus OB3
Sunay Ibryamov, Gabriela Zidarova, Evgeni Semkov +1
Results from optical CCD photometric observations of 13 pre-main-sequence stars collected during the period from February 2007 to November 2020 are presented. These stars are locat…
The symbiotic binary ZZ CMi: intranight variability and suggested outbursting nature
R. K. Zamanov, K. A. Stoyanov, A. Kostov +9
We present photometric and spectral observations of the symbiotic star ZZ CMi. We detect intranight variability - flickering and smooth variations in U band. The amplitude of the f…
Radius, rotational period and inclination of the Be stars in the Be/gamma-ray binaries MWC 148 and MWC 656
R. K. Zamanov, K. A. Stoyanov, J. Marti +2
Using TESS photometry and Rozhen spectra of the Be/gamma-ray binaries MWC 148 and MWC 656, we estimate the projected rotational velocity (), the rotational period (P$_…
Pollux: A weak dynamo-driven dipolar magnetic field and implications for its probable planet
M. Aurière, P. Petit, P. Mathias +7
Context: Pollux is considered as an archetype of a giant star hosting a planet. We then discovered a weak magnetic field at its surface using spectropolarimetry. Aims and Methods:…