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Record W1561821896 · doi:10.1086/301417

W UMa-Type Binary Stars in Globular Clusters

2000· article· en· W1561821896 on OpenAlexaff
S. M. Ruciński

Bibliographic record

VenueThe Astronomical Journal · 2000
Typearticle
Languageen
FieldPhysics and Astronomy
TopicStellar, planetary, and galactic studies
Canadian institutionsUniversity of Toronto
Fundersnot available
KeywordsGlobular clusterAstrophysicsPhysicsBlue stragglerCluster (spacecraft)StarsMetallicityContact binaryAmplitudeOpen clusterStar clusterAstronomyBinary star

Abstract

fetched live from OpenAlex

A sample of 86 contact binary systems in 14 globular clusters with available color index data in B - V or in V - I has been analyzed. A large fraction of all systems (at least one-third) are numerous foreground Galactic disk projections over long lines of sight to the clusters. Since the selection of the cluster members has been based on the M V (log P ,color) calibrations, the matter of a metallicity correction required particular attention with the result that such a correction is apparently not needed at the present level of accuracy. Analysis of the color-magnitude and period-color relations shows that globular cluster members have different properties from the Galactic disk contact systems: They are underluminous mainly because of the smaller sizes and, consequently, have shorter orbital periods; the color-index effect of the diminished blanketing is relatively less important, especially for V - I . Among the class 1 members (deviations in M V smaller than 0.5 mag), the most common are blue straggler (BS) systems. The variability amplitudes for the BS systems show a significantly different distribution from that for systems below the turn-off point (TOP): The BS systems in the sample have only small amplitudes (which may be an indication of small mass ratios), while the distribution for the systems below the TOP is peculiar in containing only large-amplitude systems. This difference may be linked to the relatively small number of the detected main-sequence contact systems below the TOP as resulting from an observational selection effect due to the rapidly increasing measurement difficulties below the TOP. As a consequence, efforts at determining the frequency of occurrence of the contact systems below the TOP have been judged to be premature. The frequency among the BS stars could be moderately well established at about 45 ± 10 BS stars per one contact BS binary; thus, contact binaries are about 3 times more common among the BS stars than among the disk population dwarfs. Contact binary systems with periods longer than 0.6 days are absent in the sample, possibly because the more massive stars have left the contact binary domain.

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 imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.002
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.007
Threshold uncertainty score0.013

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.002
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0020.002
Science and technology studies0.0010.000
Scholarly communication0.0010.000
Open science0.0000.001
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0010.000

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 head0.010
GPT teacher head0.224
Teacher spread0.214 · 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 source (direct Gemma or distilled Codex), 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

Citations100
Published2000
Admission routes1
Has abstractyes

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