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
25 papers · 1 filter
High Energy Processes in Wolf-Rayet Stars
Stephen L. Skinner, Werner Schmutz, Manuel Guedel +1
Wolf-Rayet (WR) stars are massive (10 M) evolved stars undergoing advanced nuclear burning in their cores, rapidly approaching the end of their lives as supernovae.…
AGILE, Fermi, Swift, and GASP-WEBT multi-wavelength observations of the high-redshift blazar 4C 71.07 in outburst
S. Vercellone, P. Romano, G. Piano +56
The flat-spectrum radio quasar 4C 71.07 is a high-redshift (), -loud blazar whose optical emission is dominated by the thermal radiation from accretion disc. 4C 7…
Spectral observations of X Persei: Connection between H-alpha and X-ray emission
R. Zamanov, K. A. Stoyanov, U. Wolter +2
We present spectroscopic observations of the Be/X-ray binary X Per obtained during the period 1999 - 2018. Using new and published data, we found that during "disc-rise" the expans…
The W UMa binaries USNO-A2.0 1350-17365531, V471 Cas, V479 Lac and V560 Lac: light curve solutions and global parameters based on the GAIA distances
Diana P. Kjurkchieva, Velimir A. Popov, Yordanka Eneva +1
We present photometric observations in Sloan filters g', i' of the eclipsing W UMa stars USNO-A2.0 1350-17365531, V471 Cas, V479 Lac and V560 Lac. The sinusoidal-like O-C diagram o…
A Study of the High-Luminosity Quasar HS 1946+7658
B. Mihov, L. Slavcheva-Mihova
We study the variability of the quasar HS 1946+7658 on intra-night time scale based on both our own optical and archival X-ray data. We find the quasar non-variable during about 11…
An XMM-Newton observation of the symbiotic star AG Peg: the X-ray emission after the end of its 2015 outburst
Svetozar A. Zhekov, Toma V. Tomov
We present an analysis of the XMM-Newton observation of the symbiotic star AG Peg, obtained after the end of its 2015 outburst. The X-ray emission of AG Peg is soft and of thermal…
(121514) 1999 UJ7: A primitive, slow-rotating Martian Trojan
G. Borisov, A. A. Christou, F. Colas +3
Aims. The goal of this investigation is to determine the origin and surface composition of the asteroid (121514) 1999 UJ7, the only currently known L4 Martian Trojan asteroid. Meth…
The extreme HBL behaviour of Markarian 501 during 2012
M. L. Ahnen, S. Ansoldi, L. A. Antonelli +276
A multiwavelength campaign was organized to take place between March and July of 2012. Excellent temporal coverage was obtained with more than 25 instruments, including the MAGIC,…
Rotational variation of the linear polarisation of the asteroid (3200) Phaethon as evidence for inhomogeneity in its surface properties
G. Borisov, M. Devogèle, A. Cellino +23
Asteroid (3200) Phaethon is a Near-Earth Apollo asteroid with an unusual orbit that brings it closer to the Sun than any other known asteroid. Its last close approach to the Earth…
Response to comment on "An excess of massive stars in the local 30 Doradus starburst"
F. R. N. Schneider, H. Sana, C. J. Evans +29
Farr and Mandel reanalyse our data, finding initial-mass-function slopes for high mass stars in 30 Doradus that agree with our results. However, their reanalysis appears to underpr…
The VLT-FLAMES Tarantula Survey. XXIX. Massive star formation in the local 30 Doradus starburst
F. R. N. Schneider, O. H. Ramírez-Agudelo, F. Tramper +24
The 30 Doradus (30 Dor) nebula in the Large Magellanic Cloud (LMC) is the brightest HII region in the Local Group and a prototype starburst similar to those found in high redshift…
The recurrent nova RS Oph - simultaneous B and V band observations of the flickering variability
R. K. Zamanov, S. Boeva, G. Y. Latev +7
We performed 48.6 hours (in 28 nights) of simultaneous B and V band observations of the flickering variability of the recurrent nova RS Oph in quiescence. During the time of our ob…
The phase-polarization curve of asteroid (3200) Phaethon
M. Devogèle, A. Cellino, G. Borisov +10
A multi-colour phase-polarization curve of asteroid (3200)~Phaethon has been obtained during the December 2017 apparition by merging measurements taken at the observing station of…
Implications of the Small Spin Changes Measured for Large Jupiter-Family Comet Nuclei
Rosita Kokotanekova, Colin Snodgrass, Pedro Lacerda +3
Rotational spin-up due to outgassing of comet nuclei has been identified as a possible mechanism for considerable mass-loss and splitting. We report a search for spin changes for t…
Lightcurve and rotation period determination for asteroid 3634 Iwan
Z. Donchev, E. Vchkova Bebekovska, A. Kostov +1
Lightcurve of the asteroid 3634 Iwan observed at the Bulgarian National Astronomical Observatory Rozhen in 2017 is presented. The asteroid was observed only one night, on 22 March…
NSVS 2569022: a peculiar binary among the W UMa stars with extremely small mass ratios
Diana P. Kjurkchieva, Velimir A. Popov, Nikola I. Petrov
Photometric observations of the W UMa binary NSVS 2569022 are presented. The light curve solution reveals that both components are of F spectral type (temperatures ==6100…
Long-term BVRI photometric light curves of 15 PMS stars in the IC 5070 star-forming region
Sunay Ibryamov, Evgeni Semkov, Teodor Milanov +1
This paper reports the results from the multicolor photometric observations of 15 pre-main sequence stars collected in the period 2010 September - 2017 October. The stars from our…
Evolution of the magnetic field of Betelgeuse from 2009 - 2017
P. Mathias, M. Aurière, A. López Ariste +14
Betelgeuse is an M-type supergiant that presents a circularly polarized (Stokes V) signal in its line profiles, interpreted in terms of a surface magnetic field. The weak circular…
Spectroscopic and physical parameters of Galactic O-type stars. III. Mass discrepancy and rotational mixing
Nevena Markova, Joachim Puls, Norbert Langer
Massive stars play a key role in the evolution of the Universe. Our goal is to compare observed and predicted properties of single Galactic O stars to identify and constrain uncert…
The ever-surprising blazar OJ 287: multi-wavelength study and appearance of a new component in X-rays
Pankaj Kushwaha, Alok C. Gupta, Paul J. Wiita +21
We present a multi-wavelength spectral and temporal investigation of OJ 287 emission during its strong optical-to-X-ray activity between July 2016 - July 2017. The daily -ray fl…
Characterizing optical variability of OJ 287 in 2016 - 2017
Alok C. Gupta, Haritma Gaur, Paul J. Wiita +22
We report on a recent multi-band optical photometric and polarimetric observational campaign of the blazar OJ 287 which was carried out during September 2016 -- December 2017. We e…
New polarimetric and spectroscopic evidence of anomalous enrichment in spinel-bearing Calcium-Aluminium-rich Inclusions among L-type asteroids
M. Devogèle, P. Tanga, A. Cellino +14
Asteroids can be classified into several groups based on their spectral reflectance. Among these groups, the one belonging to the L-class in the taxonomic classification based on v…
Solar Imaging using Low Frequency Arrays
C. Lonsdale, L. Benkevitch, I. Cairns +8
Low frequency imaging radio arrays such as MWA, LWA and LOFAR have been recently commissioned, and significantly more advanced and flexible arrays are planned for the near term. Th…
V2492 Cygni: Optical BVRI variability during the period 2010-2017
Sunay I. Ibryamov, Evgeni H. Semkov, Stoyanka P. Peneva
Results from BVRI photometric observations of the young stellar object V2492 Cyg collected during the period from August 2010 to December 2017 are presented. The star is located in…