Related papers: CK Aqr time keeping. Evidence for a third body
The orbital dynamics of Cyg X-3 are a key to understanding this enigmatic X-ray binary. Recent observations by the RXTE ASM and the OSSE instrument on GRO enable us to extend the baseline of arrival time measurements and test earlier models…
Our aim is to precisely measure the physical parameters of the eclipsing binary IO Aqr and derive a distance to this system by applying a surface brightness - colour relation. Our motivation is to combine these parameters with future…
We have attempted to establish an observational evidence for presence of distant companions which may have acquired and/or absorbed the angular momentum during evolution of multiple systems thus facilitating or enabling formation of contact…
A nonlinear nature of the binary ephemeris of Cygnus X-3 indicates either a change in the orbital period or an apsidal motion of the orbit. We have made extended observations of Cygnus X-3 with the Pointed Proportional Counters (PPCs) of…
Constant orbital period ephemerides of eclipsing binaries give the computed eclipse epochs (C). These ephemerides based on the old data can not accurately predict the observed future eclipse epochs (O). Predictability can be improved by…
Photometric analysis of $BVR_C$ light curves of newly discovered eclipsing binary GSC 0008-00901 is presented. The orbital period is improved to 0.28948(11) days. Photometric parameters are determined, as well. The analysis yielded to…
Four-color charge-coupled device (CCD) light curves in $B$, $V$, $Rc$ and $Ic$ bands of the total-eclipsing binary system, V1853 Ori, are presented. By comparing our light curves with those published by previous investigators, it is…
Context: New eclipse minimum timings of the M4.5/M4.5 binary CM Dra were obtained between the years 2000 and 2007. In combination with published timings going back to 1977, a clear non-linearity in observed-minus-calculated (O-C) times has…
The light-time effect method, its limitations and applications were studied. A powerful combined method of simultaneous analysis of the O-C diagrams and astrometric orbit in triple eclipsing-astrometric binaries was presented. Eleven…
We reported a cyclic variation of $O-C$ diagram with a semi-amplitude of 0.0033 days and a period of 1.05 years for the pulsating eclipsing binary HZ Dra. The cyclic variation can be explained by the light travel-time effect via the…
We combine more than 40 years of eclipse timings of the intermediate polar FO Aqr and derive new orbital ephemerides. The eclipse times are best fit with a second order polynomial, implying an $8\sigma$ detection of a period derivative. The…
V606 Centauri (V606 Cen) is an early B-type close binary with an orbital period of 1.4950935\,d and the complete light curves are very difficult to be observed on the ground. By analyzing the unbroken and continuous light curve obtained by…
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 Cyg, V345 Gem, AK Her, V502 Oph, V566 Oph, V2612 Oph, V1363…
We report on a study of eclipse timing variations in contact binary systems, using long-cadence lightcurves in the Kepler archive. As a first step, 'observed minus calculated' (O-C) curves were produced for both the primary and secondary…
Delta Cir is known as an O7.5 III eclipsing and spectroscopic binary with an eccentric orbit. Penny et al. discovered the presence of a third component in the IUE spectra. The eclipsing binary and the third body revolve around a common…
In this research, five eclipsing binary stars were studied: AB Cas, AF Gem, AR Boo, BF Vir and CL Aur. The large sets of moments of minima were used: from the international BRNO database and amateur observations from the database AAVSO.…
We present the search for eclipsing binaries with a pulsating component in the first catalogue of optically variable sources observed by OMC/INTEGRAL, which contains photometric data for more than 1000 eclipsing binaries. Five objects were…
YZ Phe is a very short-period contact binary (Sp.= $K2\,V$) with an orbital period of 0.2347 days near the short period limit (0.22 d). We present the complete light curves in $VRI$ bands, which photometric data were obtained with the…
Variability of the spin period of the white dwarf in the V405 Aur (RX J0558.0+5353) system using our observations and previously published maxima timings is analyzed. As the phase light curve contains two nearly equal photometric waves, one…
Multi-color photometric light curves of NO Cam in $V$ $R_C$ and $I_C$ bands are obtained and analyzed simultaneously using the Wilson-Devinney (W-D) program. The solutions suggest that NO Cam is an A-subtype overcontact binary with its mass…