Abstract Photometric observations in Sloan g′ and i′ bands of four W UMa stars, NSVS 2244206, NSVS 908513, CSS J004004.7+385531 and VSX J062624.4+570907, are presented. The light curve solutions reveal that all targets have overcontact configurations with fillout factors within 0.15–0.26. Their components are G-K spectral types and are almost in thermal contact. They are also relatively close in size and luminosity: the radius ratios r2/r1 are within 0.75–0.90; the luminosity ratios l2/l1 are within 0.53–0.63. The results of the light curve solution of CSS J004004.7+385531 imply the weak limb-darkening effect of its primary component and possible presence of additional absorbing features in the system.
Keywords methods: data analysis — stars: fundamental parameters — stars: binaries: eclipsing: individ- ual (NSVS 2244206, NSVS 908513, CSS J004004.7+385531, VSX J062624.4+570907)
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