This study presents a new configuration within the collinear elliptic Sitnikov five-body problem, characterized by two distinct pairs of primary bodies. Each pair exhibits symmetry in both shape and size, with the first pair having a greater magnitude than the second. All primary bodies are positioned collinearly and move along elliptical trajectories around their common center of mass. The primary aim of this research is to investigate the existence of equilibrium points and analyze their linear stability. The investigation focuses on the dependency of equilibrium points \(E_{1,2}\; (0,0,\zeta _{1,2})\) on three key factors: the mass parameter \(\mu ^{*}\) , the radiation factor q, and the eccentricity e of the elliptic orbits of primaries around their common center of mass. It is shown that the radiation factor q is constrained by the mass parameter within the range \(q\in (-\beta , -\beta /8)\) ; \(\beta =2\mu ^{*}/(1-2\mu ^{*})\) . By fixing \(\mu ^{*}\) , we delineate the range of q for which the equilibrium points exist, establishing that they do not exist outside this range. The study reveals that as the eccentricity e increases toward 1, the equilibrium points \(E_{1,2}\) converge toward the center of mass along the \(\zeta \) -axis, while a decrease in e toward 0 causes them to move away. Similarly, as q approaches \(-\beta /8\) , \(E_{1,2}\) move closer to the center of mass, and as q approaches \(-\beta \) , they move farther away. The analysis demonstrates that all equilibrium points identified in this study exhibit linear instability. These results offer a detailed understanding of the positional dynamics of equilibrium points as a function of the mass parameter, radiation factor, and orbital eccentricity. The findings have significant implications for the fields of Celestial Mechanics and Dynamical Astronomy. Finally, the study also explores the motion of the infinitesimal mass using first return map and families of periodic orbits to reveal the system’s dynamic behavior.
