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Record W2020812440 · doi:10.1086/342449

CCD Observations of the Open Cluster NGC 6939

2002· article· en· W2020812440 on OpenAlexaff
J. M. Rosvick, D. D. Balam

Bibliographic record

VenueThe Astronomical Journal · 2002
Typearticle
Languageen
FieldPhysics and Astronomy
TopicStellar, planetary, and galactic studies
Canadian institutionsUniversity of VictoriaDominion Astrophysical ObservatoryHerzberg Institute of Astrophysics
Fundersnot available
KeywordsPhysicsDistance modulusOpen clusterAstrophysicsMetallicityPhotometry (optics)Cluster (spacecraft)AstronomyStars

Abstract

fetched live from OpenAlex

New B , V , and I CCD photometry is presented for the intermediate-age open cluster NGC 6939. V , B - V and V , V - I color-magnitude diagrams (CMDs), which extend 4 mag fainter than previous CMDs, have been constructed. The CMDs show a clearly defined turnoff and well-populated red giant clump, suggesting a cluster age of at least 1 Gyr. A comparison between the clump stars of this cluster and those of the open cluster NGC 752 indicate a color excess and distance modulus of 0.33 ± 0.07 and 12.27 ± 0.41 mag, respectively. Examination of reddening maps and CMDs of different quadrants of the cluster suggest that variable reddening across the face of the cluster is present. Color excess values and distance moduli for four quadrants of the cluster range from 0.29 to 0.41 mag and 12.21 to 12.39 mag. Comparison between the V , B - V CMD and solar metallicity isochrones yield a cluster age of 1.6 ± 0.3 Gyr.

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)0.000
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 score0.062
Threshold uncertainty score0.123

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0010.001
Science and technology studies0.0010.000
Scholarly communication0.0000.000
Open science0.0000.001
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0020.001

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 head0.044
GPT teacher head0.241
Teacher spread0.197 · 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

Citations9
Published2002
Admission routes1
Has abstractyes

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