Abstract This paper investigates a simplified model for describing the gravitational fields of non-axisymmetric elongated asteroids. The connection between the simplified model and the target asteroid is built by considering the positions of equilibrium points. To improve the performance of position matching for the equilibrium points associated with these non-axisymmetric asteroids, a non-axisymmetric triple-particle-linkage model is proposed based on two existing axisymmetric particle-linkage models. The unknown parameters of the simplified model are determined by minimizing the matching error using the nonlinear optimization method. The proposed simplified model is applied for three realistic elongated asteroids, 243 Ida, 433 Eros and (8567) 1996 HW1. The simulation results verify that the current particle-linkage model has better matching accuracy than the two existing particle-linkage models. The comparison, between the simplified model and the polyhedral model, on the topological cases of the equilibrium points and the distribution of gravitational potential further validate the rationality and accuracy of the simplified model.
Keywords asteroids: individual (243 Ida, 433 Eros, (8567) 1996 HW1) — celestial mechanics — gravitation
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