SIMBAD references

This paper reports new four-filter CCD observations of the contact binary FU Dra. The Wilson and Devinney model was used to simultaneously fit these light curves and published radial velocity data. The stellar masses, sizes, and densities were calculated. Five additional models involving dark spots, hot spots, and accretion heating were considered as explanations for the light curve asymmetry known as the "O'Connell effect" in FU Dra. No conclusive spot model choice could be made but the Liu and Yang model for accretion heating is an unlikely explanation for the O'Connell effect in FU Dra.