Non-gravitational parameters and orbital stability of asteroids in retrograde orbits

We studied the dynamical evolution of all numbered and selected unnumbered asteroids in a retrograde orbit. We computed the absolute magnitude, size range, and non-gravitational parameters A2 and Lyapunov times during the 2 Myr forward and backward orbital evolution of all 21 studied retrograde asteroids. We also studied non-gravitation parameters of 10 unnumbered retrograde asteroids brighter than 18.1 mag. It turns out that the values of A2 are of a similar order as for comets, i.e. on average, a few orders more than in the case of asteroids that are moving in prograde orbits. We investigated how the change of the non-gravitational effect influences the Lyapunov time and the evolution of the semimajor-axis-selected retrograde orbits during the forward and backward integration. We also indicated the roles of Lidov-Kozai resonance in the orbital evolution of the retrograde asteroid.