Origin of anomalously low i-band reflectance

Investigate the origin of the anomalously low i-band reflectance observed for asteroid 2026 DO14 in its Rubin Observatory griz-derived reflectance spectrum, which is not explained by residual rotational modulation.

Background

The paper derives asteroid colors and low-resolution reflectance spectra from Rubin Observatory griz photometry and compares them with representative taxonomic spectra. For asteroid 2026 DO14, both the Lomb–Scargle and high-order Fourier period solutions produce a red spectral slope broadly consistent with a D-type classification, but the measured i-band reflectance is substantially lower than expected. The authors tested whether the discrepancy could be caused by residual rotational variability and found that it could not, leaving the physical or observational origin of the anomaly unresolved. Resolving this issue is important for assessing the reliability of photometric taxonomy and reflectance-based compositional interpretation from sparse Rubin data.