2025MNRAS.537.1879O

Such spectroscopic and photometric studies have opened up a window into the interiors of solar-type stars that are found in eclipsing binaries, which is proving to be a remarkable facility of knowledge to test models of stellar evolution. Until recently, numerous cases had been analysed using Kepler data. To further clarify this research, we investigate four long-period detached eclipsing binaries: KIC 8868907, KIC 8610483, KIC 9948002, and KIC 11769146. Our findings revealed that the target systems are composed of solar-type components in a wide and very eccentric orbit. Simultaneous orbital and light-curve solutions indicate that the computed stellar radii and masses of the components of KIC 8868907, KIC 9948002, and KIC 11769146 align with theoretical models within the uncertainties. We observe a curious case for KIC 8610483 whose components are very likely main-sequence stars and possess lower mass than our Sun but are positioned very close to the terminal age main sequence due to their significantly large radii compared to a classical main-sequence star with a similar mass. Predictions of circularization theories suggest that none of the target systems will reach a circular orbit before the end of their main-sequence phases.