2025PASJ...77..746K

Recent studies indicate that the physical properties of eclipsing binaries can be extracted from the derivatives of their light curves. A classification scheme for the derivatives of light curves would be helpful for identifying the key characteristics of eclipsing binaries. In this study, we propose a new classification method for the light curves of overcontact eclipsing binaries by using their derivatives. We synthesized 89670 sample light curves of overcontact binaries and categorized them into five types on the basis of their first to fourth derivatives. For each type, we examined the statistical distributions of four parameters: the mass ratio, orbital inclination, fill-out factor, and eclipse obscuration. Their distributions demonstrated that parameter values exhibit certain trends depending on the classified types. With the proposed classification method, the general properties of overcontact binaries can be understood, providing a foundation for further detailed analysis.