Light-curve analysis and orbital period change of the extreme mass-ratio overcontact binary AW CrB
Bibliographic record
Abstract
Extreme mass-ratio contact binaries with a high degree of overcontact may be in the late evolutionary stages of the contact phase. Detailed photometric analyses and orbital period studies of those systems can provide invaluable information for the coalescence scenario of close binary systems, as recently observed in V1309 Sco. In this paper the first light-curve analysis and period study for the totally eclipsing contact binary AW CrB is presented. The VRcIc CCD photometric light curves are analysed by means of the WD code. The asymmetry of the light curves is modelled by a cool star spot on the primary component. It is shown that AW CrB has a high degree of overcontact f = 75 per cent and an extreme mass-ratio of q = 0.10, placing it among the few contact binaries with the lowest known mass-ratios. The mean density of the primary component suggests that it has evolved away from the zero age main sequence (ZAMS). Eighty-four times of minimum light are reported, derived from observations available in public archives, the literature and the observations presented in this paper. The orbital period study shows a continuously increasing period, at a rate of dP/dt = 3.58 × 10−7 d yr−1, suggesting a mass transfer from the secondary component to the primary one, implying a further decreasing mass-ratio.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 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 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".