SIMBAD references

Contact binaries at various stages of evolution unveil various operating mechanisms that drive them. We report the photometric and period variation analysis of two contact binaries EV Cnc and AH Cnc in open cluster M67. We observed the cluster from the JCBT 1.3 m telescope and utilized TESS and Kepler observations. The photometric solutions of EV Cnc and AH Cnc revealed a mass ratio of q ∼ 0.41 and ∼0.15 with an inclination of i = 42° and 87° respectively. These solutions suggest that EV Cnc is probably a semi-detached and AH Cnc is a deep low-mass ratio contact binary. The study of O - C variation analysis indicates that for both systems, the period is increasing which suggests the mass transfer is occurring from secondary to primary. In the case of AH Cnc and based on simulations by randomly varying the time of minima to fit the LITE solution, we noted the third body orbital period to be around P₃ = 26.82 ± 2.54 yr, which is different from earlier reported values and conclude that future observations are required to confirm this scenario. We compare these two systems with other similar contact binaries to get an estimate of the final configuration of the respective systems.