A Search for Evolutionary Changes in the Periods of Cepheids Using Archival Data from the Harvard Observatory Plate Collection. III. GY Sagittae
Bibliographic record
Abstract
A total of 1095 magnitude estimates for the long‐period classical Cepheid GY Sge (P = 51 days), derived from the photographic plate collections of Harvard College Observatory, Sonneberg Observatory, and Sternberg Astronomical Institute, were combined with 48 new radial velocity measures obtained using the correlation spectrometer on the 1 m reflector of the Crimean Astrophysical Observatory. The data, in combination with published photometry (including observations from the All Sky Automated Survey 3) and radial velocity measurements, cover a time baseline spanning 116 years. The resulting O - C data display evolutionary changes in the period of GY Sge amounting to + 203 ± 27 s yr −1 , a value in good agreement with theoretical predictions for a star in the third crossing of the instability strip. Large cyclical drifts with durations of ∼23,000 days superposed on the parabolic evolutionary trend in the O - C data exhibit the positive signature of random fluctuations in pulsation period, of magnitude similar to what is found in other pulsating stars of similar period.
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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.004 | 0.003 |
| 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".