Yarkovsky effect and solar radiation pressure on the orbital dynamics of the asteroid (101955) Bennu

In this paper, the orbital perturbation of near-Earth asteroid Bennu due to Yarkovsky effect and solar radiation pressure (SRP) is studied. The physical model of the astroid Bennu is used to compute Yarkovsky acceleration. The basic equation of motion is written in perturbed two body problem to show the variations in orbital elements and change in position of Bennu. The change in semi-major axis due to perturbation of Yarkovsky effect is obtained. In the presence of Yarkovsky effect, the semi-major axis decreases by 348 m over one period. The magnitude of Yarkovsky force and solar radiation pressure force is computed. We find that the maximum magnitude of Yarkovsky force and solar radiation pressure force as 0.09 N and 1.16 N, respectively, at the perihelion. It is found that Yarkovsky effect shifts the position of Bennu up to 185.2 km over 12 years of period. The position change of Bennu due to combined effect of Yarkovsky force and solar radiation pressure is 172.35 km. This study shows that the solar radiation pressure has a much smaller effect on the orbit of Bennu than Yarkovsky effect.