Two almost-contact semidetached systems : ZZ Aurigae and AX Virginis.

Photoelectric observations of ZZ Aur and AX Vir from Yunnan and Beijing observatories were analyzed by the Wilson-Devinney method. The systems are very similar to each other, and appropriate values of their mass ratios were obtained. A semidetached configuration exists where the lower-mass components are in contact with their respective Roche surface, and both of the higher-mass components very nearly fill their Roche lobes. It is shown that these systems are very close to being a critical contact configuration, and ZZ Aur and AX Vir are extremely similar to the semidetached SX Aur. It is concluded that the lower-mass (contact) component is the loser during the mass-loss phase of evolution, while the gainer (more massive component) has recently become detached from its Roche surface. It is suggested that a system of this type is at an evolutionary stage.