Department of Physics, Engineering Physics & Astronomy

Department of Physics, Engineering Physics & Astronomy
Department of Physics, Engineering Physics & Astronomy

Origin of Orbital Resonances among Extrasolar Planets and the Satellites of Jupiter

Man Hoi Lee
UC Santa Barbara

Tuesday, October1, 2002
11:30 AM @ Stirling 201

Abstract:

The orbits of the two planets about the star GJ 876 have periods that are nearly in the ratio 2:1 and are in a remarkable set of three resonances. I will discuss the unusual properties of the 2:1 resonances of this system and the likely origin of the resonances by differential orbital migration due to planet-disk interactions. Orbital resonances are likely to be ubiquitous among extrasolar planetary systems, and I will show that a large variation in the configuration of 2:1 and 3:1 resonances and, in particular, asymmetric librations can be expected among future discoveries. I will also discuss the assembly of the Laplace resonance among the Jovian satellites Io, Europa, and Ganymede (whose orbital periods are nearly in the ratio 1:2:4) by differential migration of the newly formed satellites due to satellite-disk interactions. This contrasts with the currently popular means of resonance assembly by differential orbital expansion due to tides raised on Jupiter.