Can White Dwarf Asteroseismology Really Constrain the [TSUP]12[/TSUP]C(α, γ)[TSUP]16[/TSUP]O Reaction Rate?
Bibliographic record
Abstract
In light of the recent claims that the value of the C-O ratio at the center of DB white dwarfs can be determined from asteroseismological analyses, we have reexamined the available data (11 periods) for the best-studied star of the type, GD 358. We computed improved evolutionary models that combine evolution and diffusion and that lead to structurally different equilibrium configurations than used in the previous studies. In particular, we find that diffusion leads to the formation of a double-layered configuration that leaves very strong imprints on the theoretical period spectrum of models of GD 358. We find that our double-layered models with uniform core compositions are equally successful at explaining the GD 358 data as the single-layered models with variable core compositions used in recent studies. Given that single-layered DB models can no longer be justified when diffusion is properly taken into account, we conclude that reports of determinations of the central composition of GD 358 as well as related inferences on the astrophysically important 12 C(α, γ) 16 O reaction rate are premature.
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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 | 0.001 | 0.004 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.002 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 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".