Astronomy & Astrophysics Seminar: Formation of Satellites in Circumplanetary Disks - The Uranus System

Zoom: https://tau-ac-il.zoom.us/j/87875748926?pwd=MGh1dk9DeXBxa2FEL0thMVRaaHZGQT09

Abstract:

The origin of the Uranian satellite system remains uncertain. The four major satellites have nearly circular, co-planar orbits and the ratio of the satellite system and planetary mass resembles Jupiter's satellite system, suggesting the Uranian system was similarly formed within a disk produced by gas co-accretion. However, the Uranian satellite system is unique in that Uranus is a retrograde rotator with a high obliquity. The satellites orbit in its highly tilted equatorial plane, a configuration that cannot be explained by co-accretion alone. In this work we investigate the formation of the Uranian system in the co-accretion + giant impact scenario. In this model, a satellite system formed by co-accretion is destabilized by a giant impact that tilts the planet. The primordial satellites collide and disrupt, creating an outer debris disk that can reorient to the planet’s new equatorial plane and accrete into Uranus' 4 major satellites. We here simulate giant impacts that appropriately tilt the planet and leave the system with an angular momentum comparable to that of the current system and suggest alternatives that merit further exploration.

Seminar Organizer: Dr. Iair Arcavi