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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 solutions reveal that all targets have overcontact configurations with fillout factor within 0.15-0.26. Their components are of G-K spectral type and almost in thermal contacts. They are relatively close also in size and luminosity: the radius rations r_2/r_1 are within 0.75-0.90; the luminosity ratios l_2/l_1 are within 0.53-0.63. The results of the light curve solution of CSS J004007.7+385531 imply weak limb-darkening effect of its primary component and possible presence of additional absorbing feature in the system.
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 periods turned out almost equal to the previous values. We found that
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 eclipsing systems. The light curve solutions revealed that all short-period
Using multicolour photometry we have confirmed the binary nature of the new W-type W UMa eclipsing binary VSX J053024.8+842243 and established its primary eclipse ephemeris to be HJD = 2455924.38150(26) + 0.4322929(1) * E. Using the light curve model
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 relatively well-k
We present an analysis of UBVR$_{rm C}$I$_{rm C}$JH photometry and phase-resolved optical spectroscopy of NSVS 14256825, an HW Vir type binary. The members of this class consist of a hot subdwarf and a main-sequence low-mass star in a close orbit ($P