Magnetism and binarity of the Herbig Ae star V380 Ori
Bibliographic record
Abstract
In this paper we report the results of high-resolution circular spectropolarimetric monitoring of the Herbig Ae star V380 Ori, in which we discovered a magnetic field in 2005. A careful study of the intensity spectrum reveals the presence of a cool spectroscopic companion. By modelling the binary spectrum, we infer the effective temperature of both stars: 10 500 ± 500 K for the primary and 5500 ± 500 K for the secondary, and we argue that the high metallicity ([M/H]= 0.5), required to fit the lines, may imply that the primary is a chemically peculiar star. We observe that the radial velocity of the secondary's lines varies with time, while that of the primary does not. By fitting these variations, we derive the orbital parameters of the system. We find an orbital period of 104 ± 5 d and a mass ratio (MP/MS) larger than 2.9. The intensity spectrum is heavily contaminated with strong, broad and variable emission. A simple analysis of these lines reveals that a disc might surround the binary and that a wind occurs in the environment of the system. Finally, we performed a magnetic analysis using the least-squares deconvolved profiles of the Stokes V spectra of both stars and adopting the oblique rotator model. From rotational modulation of the primary's Stokes V signatures, we infer its rotation period P= 4.312 76 ± 0.000 42 d and find that it hosts a centred dipole magnetic field of polar strength 2.12 ± 0.15 kG, with a magnetic obliquity β= 66°± 5° and a rotation axis inclination i= 32°± 5°. However, no magnetic field is detected in the secondary, and if it hosts a dipolar magnetic field, its strength must be below about 500 G, to be consistent with our observations.
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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 | 0.000 |
| Science and technology studies | 0.000 | 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".