Bibliographic record
Abstract
Optical spectra obtained in 2006–2007 of the nova-like cataclysmic variable QU Car are studied for radial velocities (RVs), line profiles, and line identifications. We are not able to confirm the reported 10.9 h orbital period from 1982, partly because our sampling is not ideal for this purpose and also, we suspect, because our RVs are distorted by line profile changes due to an erratic wind. P-Cygni profiles are found in several of the emission lines, including those of C iv . Carbon lines are abundant in the spectra, suggesting a carbon enrichment in the donor star. The presence of [O iii ] 5007 Å and [N ii ] 6584 Å is likely due to a diffuse nebula in the vicinity of the system. The wind signatures in the spectra and the presence of nebular lines are in agreement with the accretion wind evolution scenario that has been suggested to lead to SNeIa. We argue that QU Car is a member of the V Sge subclass of cataclysmic variables, and a possible SNeIa progenitor. It is shown that the recent light curve of QU Car has ∼1 mag low states, similar to the light curve of V Sge, strengthening the connection of QU Car with V Sge stars, supersoft X-ray sources, and SNeIa progenitors.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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.
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".