Absolute parameters of the W UMa binaries CSS J223614+311343, V523 Aur and V783 And

Abstract Photometric BVRc observations of the stars CSS J223614+311343, V523 Aur and V783 And were carried out and their absolute parameters (masses, radii and luminosities) were determined based on light curve modeling and Gaia distances. The main results are: (i) The components of CSS J223614+311343 and V783 And are of K spectral type while those of V523 Aur are G stars; (ii) The three systems have middle fillout factors 0.20–0.29; (iii) CSS J223614+311343 and V783 And are of A-subtype while V523 Aur is of W-subtype; (iv) The common target masses are near the lower mass limit for the known W UMa binaries; (v) The smaller in size (and less massive) components of all targets locate above the MS band of the evolutional diagrams while the bigger components are within the MS band. The only exception is the bigger component of V523 Aur that is also above the MS band. This result was attributed to the W-subtype of the target.