152 citations · 451 across the 32 of their papers we have counts for
32 papers
Physical parameters of close binary systems: VIII
K. Gazeas, S. Zola, A. Liakos +13
This paper presents the results of a combined spectroscopic and photometric study of 20 contact binary systems: HV Aqr, OO Aql, FI Boo, TX Cnc, OT Cnc, EE Cet, RWCom, KR Com, V401…
International observational campaign of the 2014 eclipse of EE Cep
D. Pieńkowski, C. Gałan, T. Tomov +64
Context. EE Cep is one of few eclipsing binary systems with a dark, dusty disk around an invisible object similar to ε Aur. The system is characterized by grey and asymmetric eclip…
New light curve solution of V568 Peg and first determination of its fundamental parameters
Diana Kjurkchieva, Sunay Ibryamov
We present V, Rc photometric observations of the short-period W UMa star V568 Peg. They allowed us to improve its period. The light curve solution revealed that V568 Peg is an over…
First observations with the 25 cm telescope of the Shumen Astronomical Observatory
Diana Kjurkchieva, Sunay Ibryamov, Borislav Borisov +3
The first observations with the 25 cm telescope of the Shumen Astronomical Observatory led to the following conclusions: (a) Intra-night observations of variable stars with an ampl…
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…
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…
Light curve solutions of the eclipsing eccentric binaries KIC 8111622, KIC 10518735, KIC 8196180 and their out-of-eclipse variability
Diana P. Kjurkchieva, Doroteya L. Vasileva
We determined the orbits and stellar parameters of three eccentric eclipsing binaries by light curve solutions of their Kepler data. KIC 8111622 and KIC 10518735 undergo total ecli…
Observations and light curve solutions of ultrashort-period eclipsing binaries
Diana P. Kjurkchieva, Dinko P. Dimitrov, Sunay I. Ibryamov +1
Photometric observations in V and I bands and low-dispersion spectra of ten ultrashort-period binaries (NSVS 2175434, NSVS 2607629, NSVS 5038135, NSVS 8040227, NSVS 9747584, NSVS 4…
Light curve solutions of the eccentric binaries KIC 10992733, KIC 5632781, KIC 10026136 and their out-of-eclipse variability
Diana Kjurkchieva, Doroteya Vasileva
We determined the orbits and stellar parameters of three eccentric eclipsing binaries by light curve solutions of their Kepler data. KIC 10992733 and KIC 5632781 undergo total ecli…
Observations and light curve solutions of the eclipsing stars CSS J075205.6+381909 and NSVS 691550
D. Kjurkchieva, V. Popov, D. Vasileva +2
The paper presents observations and light curve solutions of the eclipsing stars CSS J075205.6+381909 and NSVS 691550. As a result their initial epochs were determined. The target…
Observations and light curve solutions of the W UMa binaries V796 Cep, V797 Cep, CSS J015341.9+381641 and NSVS 3853195
D. P. Kjurkchieva, V. A. Popov, S. I. Ibryamov +2
Photometric observations in Sloan g' and i' bands of four W UMa binaries, V796 Cep, V797 Cep, CSS J015341.9+381641 and NSVS 3853195, are presented. Our observations showed that CSS…
Light curve solutions of 12 eccentric Kepler binaries and analysis of their out-of-eclipse variability
Diana Kjurkchieva, Doroteya Vasileva, Dinko Dimitrov
The eccentricity, periastron angle, orbital inclination, mass ratio, stellar temperatures and relative stellar radii of 12 eclipsing eccentric binaries were determined on the basis…
The B and Be States of the Star EM Cepheus
Diana Kjurkchieva, Dragomir Marchev, T. A. A. Sigut +1
We present eleven years of high-resolution, spectroscopic observations for the star EM~Cep. EM~Cep switches between B and Be star states, as revealed by the level of H emission,…
YETI observations of the young transiting planet candidate CVSO 30 b
St. Raetz, T. O. B. Schmidt, S. Czesla +32
CVSO 30 is a unique young low-mass system, because, for the first time, a close-in transiting and a wide directly imaged planet candidates are found around a common host star. The…
Photometric observations and light curve solutions of the W UMa stars NSVS 2244206, NSVS 908513, CSS J004004.7+385531 and VSX J062624.4+570907
D. Kjurkchieva, V. A. Popov, D. Vasileva +1
Photometric observations in Sloan g' and i' bands of four W UMa stars, NSVS 2244206, NSVS 908513, CSS J004004.7+385531, VSX J062624.4+570907, are presented. The light curve solutio…
Departure from the constant-period ephemeris for the transiting exoplanet WASP-12 b
G. Maciejewski, D. Dimitrov, M. Fernández +11
Most hot Jupiters are expected to spiral in towards their host stars due to transfering of the angular momentum of the orbital motion to the stellar spin. Their orbits can also pre…
Solution of newly observed transit of the exoplanet HAT-P-24b: no TTV and TDV signals
Diana Kjurkchieva, Dinko Dimitrov, Sunay Ibryamov
We present photometric observations of transit of the exoplanet HAT-P-24b using the Rozhen 2 m telescope. Its solution gives relative stellar radius r_{s}=0.1304 (a/R_{s}=7.669), r…
2MASSJ22560844+5954299: the newly discovered cataclysmic star with the deepest eclipse
D. Kjurkchieva, T. Khruzina, D. Dimitrov +3
Context: The SW Sex stars are assumed to represent a distinguished stage in CV evolution, making it especially important to study them. Aims: We discovered a new cataclysmic star a…
Light curve solutions of the eccentric Kepler binaries KIC 11619964 and KIC 7118545 and mid-eclipse brightening of KIC 11619964
Diana Kjurkchieva, Doroteya Vasileva
We carried out light curve solutions of two eclipsing detached binaries on eccentric orbits observed by Kepler. The orbits and fundamental parameters of KIC 11619964 and KIC 711854…
Light Curve Solutions of Ten Eccentric Kepler Binaries, Three of them with Tidally Induced Humps
D. Kjurkchieva, D. Vasileva
We carried out light curve solutions of ten detached eclipsing eccentric binaries observed by Kepler. The formal errors of the derived parameters from the light curve solutions are…
The unusual photometric variability of the PMS star GM Cep
E. Semkov, S. Ibryamov, S. Peneva +6
Results from UBVRI photometric observations of the pre-main sequence star GM Cep obtained in the period April 2011 - August 2014 are reported in the paper. Presented data are a con…
Light curve solutions of six eclipsing binaries at the lower limit of periods of the W UMa stars
Diana P. Kjurkchieva, Dinko P. Dimitrov, Sunay I. Ibryamov
Photometric observations in V and I bands of six eclipsing binaries at the lower limit of the orbital periods of W UMa stars are presented. Three of them are newly discovered eclip…
Light curve solutions of the ultrashort-period binaries
Diana Kjurkchieva, Dinko Dimitrov
We carried out light curve solutions of the ultrashort-period binaries with MS components observed by . All six targets turned out almost in thermal contact with contact or…
The stellar content of the young open cluster Trumpler 37
R. Errmann, R. Neuhäuser, L. Marschall +21
With an apparent cluster diameter of 1.5° and an age of ~4 Myr, Trumpler 37 is an ideal target for photometric monitoring of young stars as well as for the search of planetary tran…