THE NATURE OF V392 ORI: A NEAR-CONTACT BINARY WITH AδSCUTI-TYPE COMPONENT

Abstract

This study presents multi-color photometric observations of the short-period eclipsing binary V392 Ori. Taking into account the results obtained from the models and analyses of the BVRI light curves, the nature of the binary system as well as the light-curve variations were discussed. The distortions of the light curves were successfully synthesized with a cool-spot model. The photometric solutions indicated that V392 Ori is a semi-detached, near-contact system with the cooler secondary component filling and the primary nearly filling each of their Roche lobes. The mass ratio of the system is determined to be 0.247 ± 0.001, and the inclination is derived to be . Based on these results, the physical parameters of the components were estimated. The analysis indicates that the secular orbital period of the system is decreasing at a rate of −3.0 s per century, probably due to the nonconservative mass exchange and mass loss of the system, which could be the source of the long-term light-curve changes. By subtracting the theoretical light curves from the original observations, we remove the eclipse and proximity effects so as to investigate the short-term variations. Frequency analysis of the residual light reveals a periodicity of 35.5 minutes in all the BVRI bands. The nature of the intrinsic pulsations was discussed along with the evolution of the components. For the first time in the literature, we revealed that the primary component is a δ Scuti star. We thus list V392 Ori as a new candidate eclipsing binary with a δ Scuti component.