The Basics of Trans-Neptunian Dynamics
Traditionally divided into two regions:
- Kuiper belt: Predicted in 1930, 1950,& 1988 (Duncan et al.), discovered 1992 (Luu & Jewitt)
- Traditionally objects that are in primordial or nearly primordial orbits
(i.e. not scattered by planet).
- 520 objects, 239 with good orbits. (3/27/02)
- Two types of objects:
- Some Objects mainly in the mean motion resonances with Neptune.
- roughly 4% of population (biases corrected). (Trujillo et al.)
- `Main belt':
- Inner edge @ ~40AU, outside the 2:3 resonance.
- Outer edge @ 50AU? There is currently much debate whether this is real or not.
- Cannot JUST be observational biases.
- Inclinations very large, observed i'=cos-1(mean cos(i))=9O .
- However, i'=21O if corrected for observational bias (Brown)!
- These are large (>~ 100km),
requires 'cold' KB to grow (Stern & Colwell)
- Scattered Disk: Predicted in 1997 (Duncan & Levison), discovered 1997 (Luu & Jewitt)
- Traditionally thought to be objects that were gravitationally scattered by Neptune.
- 104 objects, 56 with good orbits. (3/27/02)
- Largest known a is 560AU. These are large, roughly 100km.
- Should have perihelion distances near Neptune.
 Implies what we (I?) thought last year.