Related papers: On the SW Sex-Type Eclipsing Cataclysmic Variable …
Using data from the extended Kepler mission in K2 Campaign 10 we identify two eclipsing binaries containing white dwarfs with cool companions that have extremely short orbital periods of only 71.2 min (SDSS J1205-0242, a.k.a. EPIC…
We report on 2MASS J01542930+0053266, a faint eclipsing system composed of two M dwarfs. The variability of this system was originally discovered during a pilot study of the 2MASS Calibration Point Source Working Database. Additional…
We identify SDSS J153636.22+044127.0, a QSO discovered in the Sloan Digital Sky Survey, as a promising candidate for a binary black hole system. This QSO has two broad-line emission systems separated by 3500 km/sec. The redder system at…
We find that the ROSAT source 1RXS J105010.3-140431 is a cataclysmic variable with orbital period of 88.6 minutes and a spectrum closely resembling WZ Sge. In particular, emission lines are flanked by Stark-broadened absorption wings…
In this work, we study a heterogeneous group of seven stellar systems for the first time. Despite their different distances or spectral types, all of them belong to a very rare group of quadruple systems of 2+2 architecture, where both of…
This study confirms MLS110213:022733+130617 as a new eclipsing polar. We performed optical spectroscopic, polarimetric and photometric follow-up of this variable source identified by the Catalina Real Time Transient Survey. Using the…
We present modeling of the long-term optical light curve and radial velocity curve of the binary stellar system CXOGBS J175553.2-281633, first detected in X-rays in the \textit{Chandra} Galactic Bulge Survey. We analyzed 7 years of optical…
We report the discovery of 1RXH J082623.6-505741, a 10.4 hr orbital period compact binary. Modeling extensive optical photometry and spectroscopy reveals a $\sim 0.4 M_{\odot}$ K-type secondary transferring mass through a low-state…
We present the new results of our long-term observational project to detect the small variations in the orbital periods of low-mass and short-period eclipsing binaries. About 120 new precise mid-eclipse times were obtained for three…
The binary emission-line system, particularly the binary broad-line emission system, is considered the most effective indicator of the black hole binary. A plausible example of such a system, SDSS J153636.22+044127.0, was reported as the…
We have investigated multiband optical photometric variability and stability of the H$\alpha$ line profile of the transient X-ray binary IGR J01583+6713. We set an upper limit of 0.05 mag on photometric variations in the {\it V} band over a…
We found that SDSS J094002.56+274942.0 underwent a superoutburst in 2019 February based on our observations and Zwicky Transient Facility (ZTF) data. This object showed shallow eclipses during this superoutburst and we established the…
We present high speed photometry of the Sloan Digital Sky Survey cataclysmic variable SDSS J013701.06-091234.9 in quiescence and during its 2003 December superoutburst. The orbital modulation at 79.71\pm0.01 min is double humped; the…
We find from high speed photometry of the Sloan Digital Survey cataclysmic variable candidate SDSS J161033.64-010223.3 that it has a double humped modulation, which is probably orbital, with a period of 80.52 minutes, and shows strong ZZ…
A photometric and spectroscopic investigation is performed on five W Ursae Majoris eclipsing binaries (EWs) J015818.6+260247 (hereinafter as J0158b), J073248.4+405538 (hereinafter as J0732), J101330.8+494846 (hereinafter as J1013),…
The hard X-ray source 2PBC J0658.0-1746 was proposed as an eclipsing magnetic cataclysmic variable of the polar type, based on optical follow-ups. We present the first spectral and timing analysis at X-ray energies with XMM-Newton,…
2MASS J09440940-5617117 was identified as a cataclysmic variable in 2007 by its spectrum. In this article we present optical differential photometry in the Rc band obtained using the 0.6-m telescope at Observatorio do Pico dos Dias/Brazil.…
In this paper we report on $\sim10$ years of observations of PSR J2051$-$0827, at radio frequencies in the range 110--4032 MHz. We investigate the eclipse phenomena of this black widow pulsar using model fits of increased dispersion and…
An eclipsing binary with an orbital period of 62 days has been discovered in HD 328058 and studied by UBVIcHalpha photometry. Combining the results of light curve modelling with existing stellar models and known B3-shell spectral type of…
We present an orbital solution study for the newly discovered system 1SWASP J080150.03+471433.8 by means of new CCD observations in VRI bands. Our observations were carried out on 25 Feb. 2013 using the Kottamia optical telescope at NRIAG,…