The Tarantula Massive Binary Monitoring II. First SB2 orbital and spectroscopic analysis for the Wolf-Rayet binary R145
Bibliographic record
Abstract
We present the first SB2 orbital solution and disentanglement of the massive Wolf-Rayet binary R145 (<i>P</i> = 159 d) located in the Large Magellanic Cloud. The primary was claimed to have a stellar mass greater than 300 <i>M</i><sub>⊙</sub>, making it a candidate for being the most massive star known to date. While the primary is a known late-type, H-rich Wolf-Rayet star (WN6h), the secondary has so far not been unambiguously detected. Using moderate-resolution spectra, we are able to derive accurate radial velocities for both components. By performing simultaneous orbital and polarimetric analyses, we derive the complete set of orbital parameters, including the inclination. The spectra are disentangled and spectroscopically analyzed, and an analysis of the wind-wind collision zone is conducted. The disentangled spectra and our models are consistent with a WN6h type for the primary and suggest that the secondary is an O3.5 If*/WN7 type star. We derive a high eccentricity of <i>e</i> = 0.78 and minimum masses of <i>M</i><sub>1</sub>sin<sup>3</sup><i>i</i> ≈ <i>M</i><sub>2</sub>sin<sup>3</sup><i>i</i> = 13 ± 2 <i>M</i><sub>⊙</sub>, with <i>q</i> = <i>M</i><sub>2</sub>/<i>M</i><sub>1</sub> = 1.01 ± 0.07. An analysis of emission excess stemming from a wind-wind collision yields an inclination similar to that obtained from polarimetry (<i>i</i> = 39 ± 6°). Our analysis thus implies <i>M</i><sub>1</sub> = 53<sup>+40</sup><sub>-20</sub> and <i>M</i><sub>2</sub> = 54<sup>+40</sup><sub>-20</sub> <i>M</i><sub>⊙</sub>, excluding <i>M</i><sub>1</sub> > 300 <i>M</i><sub>⊙</sub>. A detailed comparison with evolution tracks calculated for single and binary stars together with the high eccentricity suggests that the components of the system underwent quasi-homogeneous evolution and avoided mass-transfer. This scenario would suggest current masses of ≈ 80 <i>M</i><sub>⊙</sub> and initial masses of <i>M</i><sub>i,1</sub> ≈ 105 and <i>M</i><sub>i,2</sub> ≈ 90 <i>M</i><sub>⊙</sub>, consistent with the upper limits of our derived orbital masses, and would imply an age of ≈ 2.2 Myr.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 | 0.004 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| 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 teacher head, 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".