Spectral Diversity on (7) Iris and (10) Hygiea Revealed by Broadband Colors
Bibliographic record
Abstract
ABSTRACT We present evidence of surface spectral diversity on asteroids (7) Iris and (10) Hygiea based on Johnson–Cousins (B–V, V–R) and ATLAS (c–o) color indices. For Iris, B–V shows significant rotational modulation, revealing localized heterogeneities associated with features such as the Xanthos and Porphyra craters. Its B–R spectral slope, per , matches that of Q/S‐type asteroids, while phase‐resolved variations suggest combined effects of composition, topography, and illumination geometry. In contrast, Hygiea is spectrally uniform: neither B–V nor V–R varies with rotation, and its B–R slope, per , is typical of the B/C‐complex. The c–o distributions for both objects do not show a clear dependence on Earth‐based viewing geometry. We estimate the c–o index of near‐Earth asteroid as 0.5, consistent with a redder K/L‐type surface. This result indicates that c–o can discriminate between S‐ and C‐complex asteroids, similar to V–R. These findings demonstrate the diagnostic value of broadband colors for characterizing asteroid surfaces and provide new insights into the compositional and evolutionary diversity of main‐belt asteroids.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".