Orbits Close to Asteroid 4769 Castalia

摘要: We use a radar-derived physical model of 4769 Castalia (1989 PB) to investigate close orbit dynamics around that kilometer-sized, uniformly rotating asteroid. Our methods analysis provide basis for systematic studies particle any asteroid. We establish Jacobi integral exists particles orbiting this asteroid, examine the attendant zero-velocity surfaces, find families periodic orbits, and determine their stability. All synchronous orbits direct within ∼3 mean radii are unstable subject impact or escape from Castalia. Retrograde mostly stable allow asteroid surface. We derive which allows us predict conditions in about (temporary) capture hyperbolic interloper. Orbits 1.5 km immediate ejection system. Hyperbolic with aV∞< 0.4 m/sec can potentially be captured by if periapsis radius is ∼2 km. For region small, but results also apply larger asteroids whose regions would larger. We bounds on ejecta speeds either ensure re-impact as functions location Castalia's surface. The range 0.28 0.84 0 0.18 m/sec. Speeds between these two lead escape, re-impact, finite-time orbits. develop simple criterion whether could have been ejected past it will surface future.