## A study of Hilda asteroids## III. Collision velocities and collision frequencies of Hilda asteroids
The collision velocities and collision frequencies of Hilda asteroids have been investigated numerically. The collision probabilities and collision velocities have been determined from a data base of close encounters, obtained by numerical integrations of the orbits of 909 asteroids for 55 000 years. The integration included all known main-belt, Cybele, Hilda, and Trojan objects larger than 50 km in diameter. The mean collision probability is lower for Hilda asteroids than for main-belt, Cybele and Trojan asteroids. Out of ten collisions involving a Hilda object, about seven are with main-belt objects, and the other three collisions are evenly distributed among the three outer-belt groups. The collision probabilities of individual Hilda asteroids have a strong correlation with the eccentricity of their orbits, resulting in a wide range (about a factor of six) of collision probabilities among the Hilda objects. The mean collision velocity of the Hilda asteroids is 4.6 , which is 0.5 lower than the average for main-belt objects. The mean collision velocity of individual Hilda objects range from 3.3 to 6.0 .
This article contains no SIMBAD objects. ## Contents- 1. Introduction
- 2. Asteroid sample and calculations
- 3. Collision velocities
- 4. Collision probabilities
- 5. Collisional properties of individual Hilda asteroids
- 6. Conclusions
- Acknowledgements
- References
© European Southern Observatory (ESO) 1998 Online publication: July 27, 1998 |