Dynamics of the binary asteroid (379) Huenna
Résumé
We aim at studying the dynamical system of the asteroid (379) Huenna and its satellite, for which a discrepancy between its predicted and observed position was reported by DeMeo et al. (2011, Icarus, 212). We compile all the available images of the system acquired with large ground-based telescopes equipped with adaptive-optics fed camera. Based on these 40 observations covering 11 years, we determine the orbit of the satellite which is strongly affected by the gravitational influence of the Sun, as opposed to most satellites of large main-belt asteroids. Combining the mass of Huenna with a compilation of diameter estimates from the literature, we revise the estimate of its bulk density to 1491±249 kg ⋅m-3, consistent with its spectral classification as a P-type asteroid.