Related papers: WZ Cygni: a Marginal Contact Binary in a Triple Sy…
When observing the transiting extrasolar planets, we discovered a new W UMa type binary GSC 03553-00845. Following observation was carried out using the 1m telescope at Weihai Observatory of Shandong University. Complete BVR light curves…
In this paper, the first complete photometric light curves in the B, V, and R passbands for an eclipsing binary LO Com are presented, and the photometric solution for the LO Com is derived by analyzing these light curves by using the Wilson…
All available mid-eclipse times of the eclipsing binary Z Draconis are analysed, and three sets of cyclic variations with periods of 20.1, 29.96 and 59.88 yr are found. The low-amplitude variations with the period of 20.1 yr may be…
The first photometric analysis of V811 Cep was carried out. The first complete light curves of V, R and I bands are given. The analysis was carried out by Wilson-Devinney (W-D) program, and the results show that V811 Cep is a median-contact…
We present the results of a spectroscopic campaign revealing that the non-thermal radio emitter Cyg OB2 #8A is an O6 + O5.5 binary system. We propose the very first orbital solution indicating a period of about 21.9 days. The system appears…
We present results of 32 nights of CCD photometry of V1974 Cygni, from the years 1994 and 1995. We verify the presence of two distinct periodicities in the light curve: 0.0812585 day~1.95 hours and 0.0849767 d~2.04 hr. We establish that the…
The orbital period is a measure of the size of a contact binary star, and can be combined with color to predict its luminosity to a fraction of stellar magnitude. This novel application of contact binary systems currently has limitations…
We report the identification of cyclical changes in the orbital period of the eclipsing dwarf nova Z Cha. We used times of mid-eclipse collected from the literature and our new eclipse timings to construct an observed-minus-calculated…
AN Cam is a little-studied eclipsing binary containing somewhat evolved components in an orbit with a period of 21.0 d and an eccentricity of 0.47. A spectroscopic orbit based on photoelectric radial velocities was published in 1977. AN Cam…
We report the identification of cyclical changes in the orbital period of the eclipsing cataclysmic variable HT Cas. We measured new white dwarf mid-eclipse timings and combined with published measurements to construct an…
The ~15.1 years period found in the long-term UBV photoelectric and photographic photometry of the symbiotic nova V1016 Cyg is detected also in the (J-K) colour index and in the UV continuum and emission line fluxes from IUE and HUT…
The two CCD photometries of the intermediate polar TV Columbae are made for obtaining the two updated eclipse timings with high precision. There is an interval time \sim 17yr since the last mid-eclipse time observed in 1991. Thus, the new…
This work describes the analysis of 64 early-type, massive contact or near-contact eclipsing systems from the Large Magellanic Cloud discovered by the OGLE-III survey. It presents the determination of the period-luminosity-colour relation…
Comprehensive photometric investigation was carried out to the early K-type contact binary - IL Cnc. A few light curves from both ground-based telescopes and the Kepler space telescope were obtained (or downloaded) and then analyzed in…
Fifty archival radio observations of the supergiant binary Cyg OB2 #5 using the Very Large Array over 20 years are re-examined to determine the location and character of the previously detected variable radio emission. The radio emission…
RZ Cas is a short-period Algol-type system showing episodes of mass transfer and Delta Sct-like oscillations of its mass-gaining primary component. We analyse high-resolution spectra of RZ Cas that we obtained during a spectroscopic…
Double Periodic Variables (DPV) are among the new enigmas of semi-detached eclipsing binaries. These are intermediate-mass binaries characterized by a long photometric period lasting on average 33 times the orbital period. We present a…
The radio emission from the well-studied massive stellar system Cyg OB2 #5 is known to fluctuate with a period of 6.7 years between a low-flux state when the emission is entirely of free-free origin, and a high-flux state when an additional…
We present the photometric analysis of six short-period systems (EI Oct, V336 TrA, NX Boo, V356 Boo, PS Boo, and V2282 Cyg). This is the first photometric analysis of these systems except for V336 TrA. Observations were conducted for 27…
V498 Cyg is an early-B-type binary known to show eclipses on a period of 3.48 d, and two sets of spectral lines. We present the discovery of a second set of eclipses, on a 1.44-d period, in the light curve of this object from the Transiting…