TIC 257060897b: An inflated, low-density, hot-Jupiter transiting a rapidly evolving subgiant star
Bibliographic record
Abstract
ABSTRACT We report the discovery of a new transiting exoplanet orbiting the star TIC 257060897 and detected using TESS full frame images. We acquired HARPS-N time-series spectroscopic data, and ground-based photometric follow-up observations from which we confirm the planetary nature of the transiting body. For the host star we determined: Teff = (6128 ± 57) K, log g = (4.2 ± 0.1), and [Fe/H] = (+ 0.20 ± 0.04). The host is an intermediate age (∼3.5 Gyr), metal-rich, subgiant star with M⋆ = (1.32 ± 0.04) M⊙ and R⋆ = (1.82 ± 0.05) R⊙. The transiting body is a giant planet with a mass mp =(0.67 ± 0.03) Mj, a radius rp = (1.49 ± 0.04) Rj yielding a density ρp = (0.25 ± 0.02) g cm−3 and revolving around its star every ∼3.66 d. TIC 257060897b is an extreme system having one of the smallest densities known so far. We argued that the inflation of the planet’s radius may be related to the fast increase of luminosity of its host star as it evolves outside the main sequence and that systems like TIC 257060897b could be precursors of inflated radius short period planets found around low luminosity red giant branch stars, as recently debated in the literature.
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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 | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".