Photometry and Spectroscopy of the Optical Companion to the Pulsar PSR J1740−5340 in the Globular Cluster NGC 6397
Bibliographic record
Abstract
We present photometric and spectroscopic observations of the optical companion to the millisecond radio pulsar PSR J1740-5340 in the globular cluster NGC 6397. An analysis of the photometric variability in the B , V , and I bands indicates an inclination of the system of 43 9 ± 2 1 if the optical companion fills its Roche lobe (a semidetached configuration). The spectroscopic data show a radial velocity variation with a semiamplitude of K = 137.2 ± 2.4 km s -1 , and a system velocity γ = 17.6 ± 1.5 km s -1 , consistent with cluster membership. We use these results to derive a mass of the optical companion of M 1 = 0.296 ± 0.034 M ⊙ and M 2 = 1.53 ± 0.19 M ⊙ for the pulsar. There is evidence for secular change of the amplitude of the optical light curve of the variable measured over 7 years. The change does not have interpretation and its presence complicates reliable determination of the absolute parameters of the binary.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| 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".