Collisions of Asteroids: Asteroid (596) Sheila

Abstract

Among the small bodies of the Solar System, at present, a group of bodies, called comets of the main belt, exhibiting dynamic and/or physical properties of both comets and asteroids is distinguished. One of the reasons for such manifestations may be collisions with other bodies. Asteroid (596) Sheila is one of the bodies belonging to the group of comets of the main belt. The study of its dust coma made it possible to estimate the relative velocity of the collision and the size of the body-impactor. In this paper, we searched for a possible impactor among known asteroids, comets, and meteor showers. A real of such a type body was not found, although it could be a fragment of a possible meteor shower of comet 232P/Hill. The performed simulation of close approaches of the asteroid (596) with fictitious bodies shows that the asteroid and the comet could be such an impactor. An estimate was made of the possible change in the velocity of the asteroid (596) as a result of a collision using its positional observations. 3456 observations from February 22, 1906 to the present have been used. However, the accuracy of determining the components of the change in velocity, about 1 mm s⁻¹, turned out to be insufficient for the confident determination of such a change.