Neptune migration

Figure 4 Orbital distribution of classical and resonant KBOs. The numbers at top are ratios of the orbital periods (time to complete an orbit) of the objects to the orbital period of Neptune. The objects clustered around the 3 2 resonance are Plutinos swept up by the outward migration of Neptune. The large range of orbital inclinations produces in relative collision speeds comparable to the orbital speed ( 4 km s ) (source Luu and Jewitt, 2002).

The existence of two different populations follows not only from the difference in their inclination but also from the fact they differ in color. The authors conclude that the hot population was formed by a single close stellar encounter at a distance of 80 000 AU. These caused an increase in the eccentricities of the hot population objects and their perihelia moved to 35 AU. Because of the outward migration of planet Neptune (see e.g. Levison and MorbidelU, 2003 [200]) most of them were removed, less then 10% remained in stable orbits. This is consistent with the observations of the present distribution. Neptune s migration was also studied by an N-body simulation (Hahn, Malhotra, 2005 [152]). Neptune s migration can explain Neptune s 5 2 resonance and other resonances. Also Centaurs can be produced by such simulations. It is also estimated that the total number of KBOs having radii >50 km orbiting interior to Neptune s 2 1 resonance is A 1.7 x 10. ... 

Hahn, J.M., Malhotra, R. Neptune s migration into a stirred-up Kuiperbelt a deteiiled comparison of simulations to observations. Astron. J. 130, 2392-2414 (2005)... 

Levison, H.F., Morbidehi, A. The formation of the Kuiper belt by the outward tiansport of bodies during Neptune s migration. Nature 426, 419 21 (2003)... 

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