Contact binaries form an interesting class of binaries which not only show mutual interactions through gravitationally bound periodic close orbits, but also dynamical interactions through mass transfer, angular momentum loss and modulation of their orbits due to the presence of tertiary components and magnetic activity. They are important as distance indicators and laboratories to study stellar evolutionary models. The current work highlights our photometric study of 61 totally eclipsing contact binaries from the ASAS, OGLE, HATNet, AST3 and TESS databases. Physical parameters are derived using PHOEBE. The selected binaries fall in a range of short periods (0.34-0.97 d), low mass ratios (0.076-0.504), F5-M0 spectral types, and a wide range of fillout factors (3-85%). Based on obtained fillout factors, 5 were classified as shallow/marginal contact, 41 as over-contact and 15 as deep-contact binaries. The absolute parameters are compared with those of well-studied binaries. Possible evolutionary states are discussed.

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.