<i>MOST</i>Detects<i>g</i>‐ and<i>p</i>‐Modes in the B Supergiant HD 163899 (B2 Ib/II)
Bibliographic record
Abstract
The Microvariability and Oscillations of Stars ( MOST ) satellite observed the B supergiant HD 163899 (B2 Ib/II) for 37 days as a guide star and detected 48 frequencies ≲2.8 cycles day -1 with amplitudes of a few millimagnitudes (mmag) and less. The frequency range embraces g - and p -mode pulsations. It was generally thought that no g -modes are excited in less luminous B supergiants because strong radiative damping is expected in the core. Our theoretical models, however, show that such g -modes are excited in massive post-main-sequence stars, in accordance with these observations. The nonradial pulsations excited in models between 20 M ☉ at log T eff ≈ 4.41 and 15 M ☉ at log T eff ≈ 4.36 are roughly consistent with the observed frequency range. Excitation by the Fe bump in opacity is possible because g -modes can be partially reflected at a convective zone associated with the hydrogen-burning shell, which significantly reduces radiative damping in the core. The MOST light curve of HD 163899 shows that such a reflection of g -modes actually occurs and reveals the existence of a previously unrecognized type of variable, slowly pulsating B supergiants (SPBsg) distinct from α Cyg variables. Such g -modes have great potential for asteroseismology.
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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 | 0.000 | 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) | 0.004 | 0.001 |
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".