Orbital predictions of asteroids taking
account of their mutual gravitational attraction

Makoto Yoshikawa
Communications Research Laboratory, Japan}


The effects of the mutual gravitational attraction between 
asteroids were analyzed by two N-body calculations, in which 
the Sun, the nine planets, and 4,506 asteroids were considered. 
In one calculation, the gravity of the asteroids was taken into 
account, and in the other it was ignored.  These calculations 
were carried out for a time period of about 100 years.  The 
largest difference in the positions of the asteroids between 
the two calculations is about 0.001 AU and it is found that 
the distribution of the differences of the positions between 
the two calculations is quite similar to the Cauchy distribution.  
Considering these results, orbital predictions of asteroids 
taking account of their mutual gravitational attraction are 
discussed for ephemerides and for observations of asteroids.