Rotation and pulsation in Ap stars: first light results from TESS sectors 1 and 2
Bibliographic record
Abstract
We present the first results from the Transiting Exoplanet Survey Satellite (TESS) on the rotational and pulsational variability of magnetic chemically peculiar A-type stars.We analyse TESS 2-min cadence data from sectors 1 and 2 on a sample of 83 stars.Five new rapidly oscillating Ap (roAp) stars are announced.One of these pulsates with periods around 4.7 min, making it the shortest period roAp star known to date.Four out of the five new roAp stars are multiperiodic.Three of these and the singly periodic one show the presence of rotational mode splitting.Individual frequencies are provided in all cases.In addition, seven previously known roAp stars are analysed.Additional modes of oscillation are found in some stars, while in others we are able to distinguish the true pulsations from possible aliases present in the ground-based data.We find that the pulsation amplitude in the TESS filter is typically a factor of 6 smaller than that in the B filter, which is usually used for ground-based observations.For four roAp stars we set constraints on the inclination angle and magnetic obliquity, through the application of the oblique pulsator model.We also confirm the absence of roAp-type pulsations down to amplitude limits of 6 and 13 μmag, respectively, in two of the best characterized nonoscillating Ap (noAp) stars.We announce 27 new rotational variables along with their rotation periods, and provide different rotation periods for seven other stars.Finally, we discuss how these results challenge state-of-the-art pulsation models for roAp stars.
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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 | 0.002 | 0.002 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| 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".