题 目： 报告人： 摘 要： 时 间： 地 点： 欢迎大家积极参与！ XSHD-2011-009 Chaotic Diffusion of Minor Bodies in the Solar System: Jupiter's Irregular Satellite System 题 目： Dr. Tobias Cornelius Hinse 报告人： (Korea Astronomy and Space Science Institute (KASI), Daejeon, South Korea) 摘 要： The dynamical time evolution of Jovian irregular satellites is mainly governed by solar and planetary gravitational perturbations and the satellite orbits are expected to exhibit chaotic dynamics. Usually chaotic motion arises from the existence of nearby orbital resonances (i.e mean-motion and secular resonances) and their possible overlap resulting in changes in the satellite's proper elements. For the retrograde Jovian satellites several clusters have been identified most likely pointing at a collisional history in the past. At current time a kinematic conundrum exist. Using Gauss equations the clusters exhibit an excess in their observed velocity dispersion. To reconcile their observed velocity fields with laboratory and hydro-code experiments on the collisional fragmentation of small bodies an additional dynamical mechanism is necessary to operate to further disperse a post-collisional satellite cloud. We have applied the MEGNO (Mean Exponential Growth of Nearby Orbits) technique to map and identify the location of solar mean-motion resonances and planetary secular resonances in the vicinity of retrograde satellite orbits. As an attempt to explain the current observed orbital distribution of Jovian retrograde satellites, I have carried out long-term numerical integrations of test particles to ascertain whether these mean-motion resonances are effective to introduce long-term chaotic dispersion in their orbital proper elements. 时 间： 2011年5月13日（星期五）下午14:00 地 点： （北京西路2号）紫台大楼327教室 欢迎大家积极参与！ 2011-4-8 紫金山天文台学术委员会学术交流工作委员会