The first photometric study and an estimation of the absolute elements of the misclassified poor thermal contact binary system NSV 3744 Gem

We present the first CCD Johnson-Cousins V and Rc light curves of the contact binary NSV 3744 obtained in 5 nights in January-March 2012. These observations confirm the short period (P  = 0.520 days) of the system. The presented light curves are analyzed simultaneously by means of the 2003 version of the Wilson-Devinney (WD) code. A grid of solutions for several fixed values of the mass ratio was calculated. The best fitting possible is for a mass ratio q = 0.379, a degree of contact f = 16.6% an orbital inclination i=81.1° and transit primary minimum. It was found that NSV 3744 was misclassified. Despite the fact that it shows a light curve of a β Lyrae type eclipsing binary star, our analysis leads to an A-subtype W Ursae Majoris contact binary system in poor thermal contact; the difference between the mean temperatures of the components is about 1650 K. The system seems to be another member of the class of poorly understood close binaries in or near geometrical contact but far from thermal contact. The absolute dimensions are estimated and its dynamical evolution is inferred.