After the first use of the wavelet transform method for asteroid family identification (Bendjoya et al. 1991), an improved three-dimensional wavelet cluster analysis has been developed and tested on artificial families in Bendjoya et al. (1992). The success of these tests has provided us a reliable method to detect statistically significant groupings in the proper element space. This method has now been applied to a large set of proper elements of real asteroids, computed by the refined algorithm of Milani & Knežević, version 5.7 (Milani & Knežević 1992). The family search is performed among 6479 asteroids: 4168 numbered asteroids plus 2311 multi-opposition objects. The robustness of the detected significant groupings has been tested against several parameters: two levels of statistical significance versus the occurrence of chance groupings; the use of two different metrics in the proper element space; and the presence of "noise" caused by small variations in time of the proper elements. The derived robustness parameters have led to classify the set of asteroids in groupings named dynamical families and tribes, which correspond to different ranges of the robustness parameters. Twenty six dynamical families and 10 tribes have been identified.
Astronomy and Astrophysics Supplement Series
- Pub Date:
- November 1993
- methods: statistical;
- minor planets