Methods for Truncating Disks
- A passing star tidally strips the Kuiper belt
(Melita el al. 2001; Kobayashi & Ida 2001; Levison, Morbidelli, & Dones 2004).
- An edge formed prior to planetesimal formation due to aerodynamic drag.
(Youdin & Shu 2002)
- An edge formed during planet accretion due to size-dependent radial gas drag.
- Nearby early-type stars photo-evaporated the outer regions of the solar nebula.
(Hollenbach & Adams 2003; Matsuyama et al. 2003)
- Magneto-hydrodynamic instabilities in the outer regions of the
disk prevented the formation of planetesimals in these regions
(Gammie 1996; Stone et al. 1998).
Note that many of these do not truncate nebula, but only the region where planetesimals formed.