Mid-infrared Studies of HD 113766 and HD 172555: Assessing Variability in the Terrestrial Zone of Young Exoplanetary Systems
Bibliographic record
Abstract
Abstract We present multiepoch infrared photometry and spectroscopy obtained with warm Spitzer, Subaru, and the Stratospheric Observatory for Infrared Astronomy to assess variability for the young (∼20 Myr) and dusty debris systems around HD 172555 and HD 113766A. No variations (within 0.5%) were found for the former at either 3.6 or 4.5 μ m, while significant nonperiodic variations (peak to peak of ∼10%–15% relative to the primary star) were detected for the latter. Relative to the Spitzer Infrared Spectrograph spectra taken in 2004, multiepoch mid-infrared spectra reveal no change in either the shape of the prominent 10 μ m solid-state features or the overall flux levels (no more than 20%) for both systems, corroborating the fact that the population of submicron-size grains that produce the pronounced solid-state features is stable over a decadal timescale. We suggest that these submicron-size grains were initially generated in an optically thick clump of debris of millimeter-size vapor condensates resulting from a recent violent impact between large asteroidal or planetary bodies. Because of the shielding from the stellar photons provided by this clump, intense collisions led to an overproduction of fine grains that would otherwise be ejected from the system by radiation pressure. As the clump is sheared by its orbital motion and becomes optically thin, a population of very fine grains could remain in stable orbits until Poynting–Robertson drag slowly spirals them into the star. We further suggest that the 3–5 μ m disk variation around HD 113766A is consistent with a clump/arc of such fine grains on a modestly eccentric orbit in its terrestrial zone.
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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".