Test of a low-mass contact binary model by comparing the relations obtained from theory with those from observations

The W UMa-type contact binaries have been observed for several decades. To construct the evolutionary model for W UMa-type contact binaries, many difficulties were encountered due to the existence of complicated physical processes in such systems. The model introduced by Huang, Song and Bi includes some special and unique understandings of the physical processes of contact binaries. It is necessary to test whether this model can be used for W UMa-type contact binaries. The best way to test a theoretical model is to know whether this model can explain the observational phenomena of such systems. For this aim, a comparison is performed for the relations of mass-luminosity, mass-radius, and the distribution in the HR diagram ob- tained from the model introduced by Huang et al. and those from the astronomical observations. The result of the comparison indicates that this model can be applied to W UMa-type contact binaries and can explain the observational phenomena of such binaries.