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Record W2012881615 · doi:10.1088/0004-637x/697/2/1032

THE THIRD SIGNATURE OF STELLAR GRANULATION

2009· article· en· W2012881615 on OpenAlexaff
David F. Gray

Bibliographic record

VenueThe Astrophysical Journal · 2009
Typearticle
Languageen
FieldPhysics and Astronomy
TopicStellar, planetary, and galactic studies
Canadian institutionsWestern University
Fundersnot available
KeywordsPhysicsGranulationAstrophysicsPhotosphereLine (geometry)Effective temperatureSpectral lineStarsAstronomyGeometry

Abstract

fetched live from OpenAlex

Absolute shifts of spectral-line bisectors (the third signature of granulation) are shown to follow the solar pattern, i.e., weaker lines are more blue-shifted than stronger lines, for a selection of stars on the cool side of the granulation boundary in the H–R diagram. These patterns scale to the solar case by multiplicative factors ranging from 0.53 to 2.10, which is a measure of the granulation velocity gradient through the stellar photosphere. The scale factors increase with effective temperature and are larger in giants than in dwarfs. A universal relation is constructed relating line depth to convective blueshift. The scale factors vary in concert with the first and second granulation signatures, macroturbulence, and asymmetry of spectral lines. Matching the stellar to the solar third signature also results in a determination of the apparent absolute radial velocity of the star with errors ranging from 80 to 300 m s−1, but potentially considerably smaller. The star γ Cyg, which shows reversed-C-shaped bisectors and lies on the hot side of the granulation boundary, also shows weak lines more blue-shifted than stronger lines.

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 distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.693
Threshold uncertainty score0.386

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0010.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.007
GPT teacher head0.218
Teacher spread0.211 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one teacher head, not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

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".

Quick stats

Citations121
Published2009
Admission routes1
Has abstractyes

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