The highly magnetic Wolf-Rayet binary HD 45166 resolved with VLTI/GRAVITY
Bibliographic record
Abstract
HD 45166 was recently reported to be a long-period binary comprising a B7 V star and a highly magnetic (⟨ B ⟩=43.0 ± 0.5 kG) hot Wolf-Rayet-like component, dubbed a quasi Wolf-Rayet (qWR) star in the literature. While originally proposed to be a short-period binary, long-term spectroscopic monitoring suggested a 22.5 yr orbital period. With a derived dynamical mass of 2.03 ± 0.44 M ⊙ , the qWR component is the most strongly magnetized non-degenerate object ever detected and a potential magnetar progenitor. However, the long period renders the spectroscopic orbital solution and dynamical mass estimates uncertain, casting doubts on whether the qWR component is massive enough to undergo core collapse. Here, we spatially resolve the HD 45166 binary using newly acquired interferometric data obtained with the GRAVITY instrument of the Very Large Telescope Interferometer. Due to the calibrator star being a binary as well, we implemented a new approach for visibility calibration and tested it thoroughly using archival GRAVITY data. The newly calibrated HD 45166 data revealed the unmistakable presence of a companion to the qWR component with an angular separation of 10.9 ± 0.1 mas (which translates to a projected physical separation of 10.8 ± 0.4 au), consistent with the long-period orbit. We obtained a model-independent qWR mass M qWR = 1.96 −0.54 +0.74 M ⊙ using interferometric and spectroscopic data together. This observation robustly confirms that HD 45166 is truly a long-period binary and provides an anchor point for accurate mass determination of the qWR component with further observations.
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 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 | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".