HD 34736: an intensely magnetised double-lined spectroscopic binary with rapidly rotating chemically peculiar B-type components
Bibliographic record
Abstract
ABSTRACT We report the results of a comprehensive study of the spectroscopic binary (SB2) system HD 34736 hosting two chemically peculiar (CP) late B-type stars. Using new and archival observational data, we characterize the system and its components, including their rotation and magnetic fields. Fitting of the radial velocities yields $P_\mathrm{orb}=83\rm{.\!\!^{ {\rm{d}}}}219(3)$ and $e=0.8103(3)$. The primary component is a CP He-wk star with $T_{{\rm eff}A}$$\,\,=13000\pm 500$ K and $\upsilon _{\rm e}\sin i\,$$\,\,=75\pm 3$ km s$^{-1}\,$, while the secondary exhibits variability of Mg and Si lines, and has $T_{{\rm eff}B}$$\,\,=11500\pm 1000$ K and $\upsilon _{\rm e}\sin i\,$$\,\,=110$–180 km s$^{-1}\,$. Transiting Exoplanet Survey Satellite and Kilodegree Extremely Little Telescope photometry reveal clear variability of the primary component with a rotational period $P_{\mathrm{rot}A}=1\rm{.\!\!^{ {\rm{d}}}}279\, 988\, 5(11)$, which is lengthening at a rate of 1.26(6) s yr$^{-1}$. For the secondary, $P_{\mathrm{rot}B}=0\rm{.\!\!^{ {\rm{d}}}}522\, 693\, 8(5)$, reducing at a rate of $-0.14(3)$ s yr$^{-1}$. The longitudinal component $\langle B_{\rm z}\rangle$ of the primary’s strongly asymmetric global magnetic field varies from $-6$ to +5 kG. Weak spectropolarimetric evidence of a magnetic field is found for the secondary star. The observed X-ray and radio emission of HD 34736 may equally be linked to a suspected T Tau-like companion or magnetospheric emission from the principal components. Given the presence of a possible third magnetically active body, one can propose that the magnetic characteristics of the protostellar environment may be connected to the formation of such systems.
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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 | 0.001 | 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".