Mol 12A (IRAS 05373+2349): a very young and deeply embedded high-mass Herbig Be star
Bibliographic record
Abstract
ABSTRACT Mol 12A (IRAS05373+2349) is a Class I high-mass young stellar object located at a distance of 1.59 kpc and still embedded ($A_V \simeq 12$) in its natal core. Its bolometric luminosity is $1.74 \times 10^3\, {\rm L}_\odot$. Medium-resolution spectra that, combined, cover 0.6–2.4 $\mu$m are presented. These show a large number of atomic permitted lines in emission, mostly hydrogen, C i, N i, Ca i, Ca ii, Si i, Fe i, Fe ii, and He i. The lines originate in the inner zones of an active protoplanetary disc. Notably, the He i 1.0830 $\mu$m line shows a complex P-Cygni profile, indicating the presence of strong stellar and/or inner disc winds accompanied with high accretion. From the strength of the brightest lines, we estimate the accretion luminosity and accretion rate to be $L_{\rm acc} \sim 10^3 \,{\rm L}_\odot$ and $\dot{M} \sim 10^{-5}\, {\rm M}_\odot$ y$^{-1}$. First overtone CO emission band-heads are detected at 2.3 $\mu$m, confirming the high accretion. No photospheric absorption lines are present. Multicolour photometric monitoring of Mol 12A from 2016 to 2024 is reported, based mostly on the Zwicky Transient Facility data together with additional targeted observations. The light-curves appear complex: at $\lambda < 2.5~\mu$m, Mol 12A exhibits irregular brightness dips, amounting to more than 4 mag at 1.25 $\mu$m accompanied by colour changes that suggest the occurrence of eclipses of up to $A_V \simeq 25$ of extra extinction caused by dust structures, probably fragments of the disrupted disc. The out-of-eclipse de-reddened location of Mol 12A on the HR-diagram and PARSEC isochrones suggest stellar parameters $M = 7 {\!-\! }9\, {\rm M}_\odot$, $T_{\rm eff} = 16\,000 {\!-\!} 19\,000\, {\rm K}$, $R = 3 {\!-\!} 6\, {\rm R}_\odot$, and age $\simeq 0.5$ Myr.
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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 | 0.000 |
| 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) | 0.003 | 0.002 |
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".