Trapping of Low-Mass Planets Outside the Truncated Inner Edges of Protoplanetary Discs

Understand

We investigate the migration of a low-mass ($\lesssim 10 M_\oplus$) planet near the inner edge of a protoplanetary disc using two-dimensional viscous hydrodynamics simulations.

• We employ an inner boundary condition representing the truncation of the disc at the stellar corotation radius.
• As described by Tsang (2011), wave reflection at the inner disc boundary modifies the Type I migration torque on the planet, allowing migration to be halted before the planet reaches the inner edge of the disc.
• For low-viscosity discs ($\alpha \lesssim 10^{-3}$), planets may be trapped with semi-major axes as large as $3-5$ times the inner disc radius.