Masses of binary asteroid systems with strong solar perturbations

Abstract

We give refined values for the masses for the following binary asteroid systems with strong solar perturbations: (379) Huenna, (3548) Eurybates-Queta, (3749) Balam, (88611) Teharonhiawako-Sawiskera, (160256) 2002 PD₁₄₉, (341520) Mors-Somnus, (364171) 2006 JZ₈₁, (524531) 2002 XH₉₁, 1998 WW₃₁, and 2003 QY₉₀. The masses were refined by numeric integration of the equations of motion where perturbations from the Sun’s gravity were taken into account. Assuming the satellite orbits to be close to Keplerian, the initial integration parameters and the masses of the systems can be refined by the least-squares method in which the coefficients of the conditional equations are calculated using the Keplerian motion formulae. For some systems with strong solar perturbations (2001 QW₃₂₂, 2006 BR₂₈₄, 2006 CH₆₉, (525462) 2005 EO₃₀₄, (612147) 2000 CF₁₀₅, (612687) 2003 UN₂₈₄) the masses could not be refined since the rms residuals increase when solar perturbations are taken into account, which can be caused by insufficient interval or amount of observations. For most systems, the obtained values for masses are within the error limits of the values obtained using only Keplerian model. However, for a number of satellites, the Keplerian model of motion, which does not take into account solar perturbations, gives significant deviations in the apparent positions exceeding the accuracy of modern observations. These systems are (379) Huenna, (3548) Eurybates-Queta, (3749) Balam, (160256) 2002 PD₁₄₉, and (364171) 2006 JZ₈₁. For the systems for which it was possible to refine the masses, we give elements of their satellites’ osculating orbits for the epoch close to the date of their first observation.