SIMBAD references

We performed a detailed photometric analysis of eight ultra-short period eclipsing binaries (USPEBs) using the Wilson-Devinney method. We present the modeled light curves and derived photometric solutions. The USPEBs with period (P )<=0.21 d considered in our study belong to W-subtype having shallow contact factor (f)<∼20%, high mass ratio (q)>∼0.7 and later spectral types. The absolute parameters for these short-period binaries were derived applying empirical relations. We discuss the evolutionary stage of these USPEBs using the mass-radius, color-density and period-color diagrams. The objects showed poor metallicities, and some objects were even found to be existing around fully convective limits. The period distribution of USPEBs exhibited a sharp cut-off at 0.22 d; however, we observed significant deficits for our objects in the literature. We examined the statistics of USPEBs studied to date (in terms of the distribution of period, mass ratio and component temperatures of USPEBs) and observed that a dominant distribution of component temperatures for these USPEBs was towards lower temperatures.