Kepler observations: Light shed on the hybrid<i>γ</i>Doradus –<i>δ</i>Scuti pulsation phenomenon
Bibliographic record
Abstract
Abstract Through the observational study of stellar pulsations, the internal structure of stars can be probed and theoretical models can be tested. The main sequence ‐γDoradus (Dor) andδScuti (Sct) stars with masses 1.2–2.5 M⊙are particularly interesting for asteroseismic study. The ‐γDor stars pulsate in high‐order gravity (g) modes, with pulsational periods of order of one day. TheδSct stars, on the other hand, show low‐order g and pressure (p) modes with periods of order of 2 hours. Theory predicts the existence of ‘hybrid’ stars, i.e. stars pulsating in both types of modes, in an overlap region between the instability strips of ‐γDor andδSct stars in the Hertzsprung‐Russell diagram. Hybrid stars are particularly interesting as the two types of modes probe different regions of the stellar interior and hence provide complementary model constraints. Before the advent of Kepler, only a few hybrid stars had been confirmed. The Kepler satellite is providing a true revolution in the study of and search for hybrid stars. Analysis of the first 50 days of Kepler data of hundreds of ‐γDor andδSct candidates reveals extremely rich frequency spectra, with most stars showing frequencies in both theδSct and ‐γDor frequency range. As these results show that there are practically no pureδSct or ‐γDor pulsators, a new observational classification scheme is proposed by Grigahcène et al. (2010). We present their results and characterize 234 stars in terms ofδSct, ‐γDor,δSct/‐γDor or ‐γDor/δSct hybrids (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
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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 | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| 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".