DCAPPSO: A novel approach for inverting asteroid rotational properties with applications to DAMIT and Tianwen-2 target asteroid

Abstract

This paper introduces the Dynamic Coefficient Adjustment in Parallel Particle Swarm Optimization (DCAPPSO) algorithm for inverting asteroid rotational properties from lightcurve data. DCAPPSO integrates a Cellinoid shape model with Particle Swarm Optimization (PSO), dynamic coefficient adjustment, and parallel computing, offering improved efficiency and accuracy in asteroid parameter determination. The algorithm’s performance was evaluated using simulated asteroid lightcurves and applied to 24 real asteroids from the DAMIT database, including a detailed case study of asteroid (44)Nysa and an additional discussion of asteroid (433)Eros. Results show excellent consistency with established rotational periods, with uncertainties typically ranging from ± 0.000018 to ± 0.009981 h. Pole orientation determinations demonstrate good agreement, particularly for latitude components. The algorithm’s parallel implementation achieves a speedup of 48.617x with 100 workers on multicore CPUs. DCAPPSO was also applied to asteroid (469219) Kamo’oalewa, the Tianwen-2 mission target, providing new insights into its shape and rotational properties. For Kamo’oalewa, the algorithm derived a rotational period of $0.460510h$ (27.63 min) and a pole orientation of $(134.67°,-11.39°)$. Uncertainty analysis yielded estimates of $133.52°\pm 0.01°$ for pole longitude, $-10.67°\pm 0.05°$ for pole latitude, and 0.466017 ± 0.006090 h for the rotational period. Shape analysis indicates a moderately elongated form with axis ratios $b/a\approx 0.67$ and $c/a\approx 0.56$. This research advances asteroid inversion techniques, offering an efficient tool to address increasing observational data volumes in planetary science.