Extreme Asteroids in the Pan-STARRS 1 Survey
Bibliographic record
Abstract
Abstract Using the first 18 months of the Pan-STARRS 1 survey, we have identified 33 candidate high-amplitude objects for follow-up observations and carried out observations of 22 asteroids. Four of the observed objects were found to have observed amplitude A obs ≥ 1.0 mag. We find that these high-amplitude objects are most simply explained by single rubble-pile objects with some density-dependent internal strength, allowing them to resist mass shedding even at their highly elongated shapes. Three further objects, although below the cutoff for “high amplitude,” had a combination of elongation and rotation period which also may require internal cohesive strength, depending on the density of the body. We find that none of the “high-amplitude asteroids” identified here require any unusual cohesive strengths to resist rotational fission. Three asteroids were sufficiently observed to allow for shape and spin-pole models to be determined through light curve inversion. Asteroid 45864 was determined to have retrograde rotation with spin-pole axes λ = 218° ± 10°, β = −82° ± 5° and asteroid 206167 was found to have best-fit spin-pole axes λ = 57° ± 5°, β = −67° ± 5°. An additional object not initially measured with A obs > 1.0 mag, 49257, was determined to have a shape model that does suggest a high-amplitude object. Its spin-pole axes were best fit for values λ = 112°± 6°, β = 6° ± 5°. In the course of this project, to date no large superfast rotators ( P rot < 2.2 hr) have been identified.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 teacher head, 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".