Analysis of potential locations of asteroidal moonlets

Abstract

In this study, the potential locations of asteroidal small satellites (also called moonlets) with quasi-circular mutual orbit are analysed. For the motion of the moonlets, only the solar gravity perturbation and the primary's second degree-and-order gravity field are considered. By eliminating short periodic terms, the dynamical behaviour of the Hamiltonian for the moonlets is investigated. The observational data of some high-size-ratio binary asteroids show that the orbits of the moonlets lie close to the classical Laplace equilibrium points, which reach global minimum values of the Hamiltonian. It is found that tides or Yarkovsky effects alone cannot account for the reason why the orbits of asteroidal moonlets are not exactly at the classical Laplace equilibrium points. The analysis in this study is expected to provide useful information for the potential locations of asteroidal moonlets, and contribute to principles to relate predictions to observations. © 2013 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.