Search for evolutionary changes in Cepheid periods using the Harvard plate collection: RS Puppis
Bibliographic record
Abstract
Based on photographic plates from the Harvard College Observatory, we have made 1492 magnitude estimates for the long-period classical Cepheid RS Pup $$ (P = 41\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle\cdot}$}}{d} 4) $$ . Together with the observations taken from the literature, our data have allowed us to construct an O-C diagram spanning a time interval of 135 years. The O-C diagram has the shape of a parabola, which has made it possible to determine for the first time the quadratic light elements and to calculate the rate of evolutionary increase in the period, $$ \dot P $$ = 119.3 (±3.0) s yr−1, in agreement with the results of theoretical calculations for the third crossing of the instability strip. The available data reduced by the method of Eddington and Plakidis (1929) have revealed random fluctuations in the period of ∼ $$ 0\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle\cdot}$}}{d} 225 $$ . However, they do not dominate on the O-C diagram, because the progressive evolutionary changes in the period in a 135-year interval lead to an amplitude of the evolutionary changes in the O-C residuals that exceeds the amplitude of the random fluctuations in the O-C residuals by a factor of 3.
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.003 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".