2025ApJ...992..142Z

The stellar model is still facing challenges in explaining the origin of low-mass stars and brown dwarfs. Double-lined detached eclipsing binaries with low-mass and similar components play an important astrophysical role in accurately deriving fundamental parameters, investigating stellar properties, and restricting theoretical stellar models of low-mass stars. Using high-precision light curves and Large Sky Area Multi-Object Fiber Spectroscopic Telescope spectra, we first obtained the fundamental parameters of the four detached binaries (NSVS 07453183, V644 Aur, V912 Per, and V1250 Tau). Except for V1250 Tau (q_sp∼ 0.95), the mass ratios of the other three targets are almost equal to 1, which is consistent with the core fragmentation and dynamical capture theories of binary formation. The O - C curves of these systems based on current data exhibit cyclic variations, which is due to the light-travel time effect caused by the presence of a third body. Among them, the third body of V912 Per is likely to be a stellar black hole $({M}_{3}\sin {i}_{3}=12.57{M}_{\odot })$. The O - C diagram of NSVS 07453183 shows double-cycle oscillations, which means that it is perhaps a quadruple system. The third body of NSVS 07453183 is an M3-type main-sequence star based on third light analysis, and the fourth body maybe a brown dwarf. The obtained Hertzsprung-Russell diagram based on the Modules for Experiments in Stellar Astrophysics code suggested that the components of these four targets are main-sequence stars. These four targets will gradually form Algol-type binaries in the future, which are important systems for studying the reversal of the mass ratio.