Asteroid phase curves and phase coloring effect using the ATLAS survey data

We present phase curves for over 300,000 asteroids using the ATLAS Solar System Catalog V2 (SSCAT-2), covering 301,272 objects in the orange filter and 280,953 in cyan. For 3,345 (orange) and 492 (cyan) asteroids, phase curve parameters were obtained with uncertainties below 15%. Our model, which accounts only for the apparition effect, shows strong consistency with more complex methods but requires significantly less computational time.

 

Using cross-matched taxonomy and robust two-dimensional Kolmogorov–Smirnov tests, we found that phase curve parameters (G1, G2) vary significantly with wavelength across nearly all taxonomic classes, except A-types. When comparing between filters, statistically significant differences were observed in the G1–G2 distributions, indicating wavelength-dependent behavior. Our analysis suggests that while phase coloring behaviors are observed without a clear preference for reddening or bluening at phase angles below 5°, reddening predominates in the 10°–30° range. However, these conclusions are based on extrapolated trends, and the associated uncertainties, particularly at low phase angles, remain significant.

 

Our catalog-independent algorithms are adaptable to new datasets, including future LSST data. This work opens new pathways for large-scale photometric surface analysis using efficient, scalable tools.