Precession of triaxial cometary nuclei

A phase-averaged system of equations, in which torque is averaged over a rotation about the spin axis, is used in the present modeling of cometary nuclei as homogeneous and rotating triaxial ellipsoids whose precession during perihelion passage is due to a solar heating-generated dust-and-gas jet. The results of numerical computations of the rotation axis inertial space precession with this phase-averaged system are compared with those obtained with the exact Euler-Poisson system of equations. Parameters appropriate to the Comet Halley nucleus are chosen. 15 references