Numerical Evaluation of the General Yarkovsky Effect: Effects on Semimajor Axis
Abstract
The Yarkovsky effect may play a key role in the orbital evolution of asteroids and nearEarth objects. To evaluate the acceleration under a wide range of conditions, a threedimensional finitedifference solution to the heat equation is applied to homogeneous, spherical stony bodies with 1, 10, and 100m diameters. This approach employs neither the linearized boundary conditions, the planeparallel heat flow approximation, nor the assumption of fast rotation used in earlier work. Thus we can explore a wide range of orbital elements and physical properties. Our work agrees well with earlier results in the regimes where their approximations are valid. We investigate a wide range of spin states, including both the "seasonal" (very fast rotation) and "diurnal" (zero obliquity) extremes of the Yarkovsky effect. We find that, for orbits with high eccentricity, the semimajor axis can change much faster than for circular orbits. For such orbits, the orientation of the rotation axis with respect to the direction of pericenter is critical in determining the evolution. A stony mainbelt asteroid of diameter 1 m on a higheccentricity orbit could change its semimajor axis by more than 1 AU in 1.5 Myr.
 Publication:

Icarus
 Pub Date:
 January 2001
 DOI:
 10.1006/icar.2000.6477
 Bibcode:
 2001Icar..149..222S