Physical Perturbations of the Circular Restricted Three-Body Problem: Effects on Equilibria and Periodic Orbits

The circular restricted three-body problem (CR3BP) is a standard astrophysical model, yet real systems deviate from its ideal assumptions. This article is a narrative review and synthesis of previous literature on how three perturbation classes: radiation pressure, oblateness, and drag, modify equilibria and periodic-orbit families in CR3BP dynamics. For conservative perturbations, equilibrium locations and stability become multi-parameter problems: radiation can admit nonclassical out-of-plane equilibria and, in special luminous-binary regimes, stable L1 ; two-oblateness models replace a single stability threshold with numerically mapped stability boundaries. Correspondingly, major periodic-orbit families generally persist but deform, so the main outputs are continuation branches and stability maps. In contrast, dissipative drag produces displaced equilibria and prevents persistence of conservative periodic families; reported behavior is commonly transient decay. These results translate directly into modeling guidance for libration-point mission design and for predicting co-orbital capture and decay of small bodies in drag-dominated environments.