A photometric study of centaurs 29P/Schwassmann–Wachmann and (2060) Chiron
Bibliographic record
Abstract
ABSTRACT This study presents the analysis of forced photometry data in the o and c filters of centaurs 29P/Schwassmann–Wachmann and (2060) Chiron obtained by the ATLAS network between 2015 and 2022. Centaur 29P had 24 outbursts with a median peak brightness of −3.0 and a range of −3.7 mag, regardless of spectral band. Some of these outbursts exhibited an asymmetric light curve with respect to peak brightness, with brightness decreases ranging from −0.22 to −7.6 mag h−1 and durations from 2.8 min to 1.4 d. The slope m of the photometric profile of the coma after/before and during an outburst was ≤1 and >1, respectively, reflecting an increase in brightness at the optocenter of the object. Without the outbursts, 29P has an absolute magnitudes H0 of 9.3 ± 0.2 and 9.10 ± 0.01 in the c and o filters, respectively, and activity indices of n = 11.56 ± 0.08 and 2.1 ± 0.1. Using the Lomb–Scargle periodogram, a periodicity of 0.97 d was found in the c magnitudes after perihelion, probably related to nuclear rotation. The absolute magnitude of Chiron in the HG1G2 system in the o filter is nearly constant between 2017 and 2020, with a weighted mean of 5.35 ± 0.03. In 2021, the brightness increases to H = 4.54 ± 0.03 and decreases to 5.04 ± 0.04 in 2022. This increase in 2021 is not due to outbursts that did not occur during the entire observing campaign, but is related to the increase in opposition effect.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.003 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".