The dynamical evolution and the force model for asteroid (196256) 2003 EH1

Abstract

This paper is devoted to the dynamics of asteroid (196256) 2003 EH1 which belongs to the Amor group. It is known that asteroid 2003 EH1 is associated with one of the main annual meteor showers – the Quadrantids. In this work we analyze the influence of various perturbing factors on the asteroid motion. The perturbations’ estimation was done by five different methods based on the nominal orbit evolution and the size of the initial confidence region. The most significant influences on the dynamical evolution of 2003 EH1 are gravitational forces from the Sun, major planets and the Moon, and the relativistic effects (RE) of the Sun. The Earth, the Sun and Jupiter oblateness; gravitational perturbations from Pallas, Ceres, Vesta and Pluto; and the RE of planets, the Moon, and Pluto are of less importance.The researches of chaoticity and evolution of asteroid 2003 EH1 were examined by integrating its motion equations along with 500 clones. The time interval (1000–4000 years) has been determined by integration precision estimation. We estimated the mean exponential growth factor of nearby orbits (MEGNO) and found that MEGNO < 2 only in the interval from 1700 year to 2300 year. After 2300 year the MEGNO parameter increases that indicates motion instability. It shows that the orbit may be considered as regular on the time interval of ±300 years from now, and as chaotic outside this interval. We suppose that the reasons are the frequent close approaches of the asteroid with Jupiter and the overlap of apsidal-nodal resonances.