Local fits to six TESS sectors show smaller KELT-9 b transit widths from 2019 to 2024
We measured the full width at half maximum of 88 KELT-9 b transits in six public 120-second TESS light curves. Local fits permit a free center, depth, edge scale, curvature, and asymmetry. A line fitted with equal weight to the six sector means gives a slope of -0.669 minutes per year from 2019 to 2024. The conditional 95% Student t interval is -0.823 to -0.515 minutes per year. It assumes a linear mean trend and independent sector errors with equal variance. The two 2024 sector means average 3.163 minutes below the two 2019 means. Eight fit variants retain the decrease. A separate measurement from smoothed light curves gives -0.625 minutes per year. Synthetic recovery with a different input profile gives little slope bias in the tested residual noise pool. Known orbital precession is a plausible cause. Changes in detector response, data processing, or stellar brightness remain possible errors. This study measures an empirical brightness-profile width and does not establish a unique physical cause. The package preserves all source files, archive provenance, code, event measurements, figures, and instructions. A full repeat reproduces the saved primary widths exactly.
KELT-9 b · TESS · transit width · nodal precession · gravity darkening · public astronomical data · reproducible measurement
References
8- usesdoi:10.17909/t9-nmc8-f686
The six original 120-second SPOC TESS light curves come from this collection. Saved filenames and SHA-256 hashes define the exact source snapshot.
- doi:10.3847/1538-4357/ac6b9a
This study measured KELT-9 b nodal precession from spectra and gives the physical context for later photometric width measurements.
- doi:10.3847/1538-3881/ab8fa3
This work showed the gravity-darkened asymmetric KELT-9 b transit. It motivates an asymmetric width estimator and limits geometric interpretation.
- usesdoi:10.3847/1538-3881/aba2cb
We use its 7.58695-hour stellar variation period for one baseline control.
- usesdoi:10.1051/0004-6361/202243823
We use its 0.3386-day stellar variation period for a baseline control. Its contact duration sets a scale for an illustrative synthetic profile.
- usesdoi:10.48550/arXiv.2602.01446
The TEPCat KELT-9 page links the adopted linear event-location ephemeris to this transit timing study. Our event centers remain free.
- usesLocal fits to two-minute TESS light curves show wider TOI-1518 b transits in 2024 than in 2022 sci:sha256:de9930a1539eee59399106f04065b1723caf14b79199a1ba07484f57b58518ce
Its event-level local fits and sector checks informed the measurement strategy. We wrote new code and did not reuse its software.
- Fits to twelve TESS sectors give weak evidence for wider Kepler-13 Ab transits from 2019 to 2024 sci:sha256:f9b264bff4f611658126764118a28615c43657e8d05586641f30c6aa3cec4d35
This related empirical width study gives context for sensitivity to transit profile and detector choices.
Cited by
5 publicationsPublic catalog entries on Sciscape.
- usesFits with a uniform planet and circular stellar limb give shorter mean KELT-9 b secondary eclipse duration estimates in six TESS sectors from 2019 to 2024
This record supplied the original public data snapshot and archive request records through the cited eclipse study.
- usesLocal fits to six TESS sectors do not resolve a KELT-9 b eclipse depth change from 2019 to 2024
We reuse six original TESS FITS files, their provenance and query records, and sector transit width ratios for one duration sensitivity test. We wrote new code to measure secondary eclipse depths.
- usesThe 7.59-hour KELT-9 signal is present in six TESS visits from 2019 to 2024
This is the upstream source of the six-product data snapshot credited by the immediate SCI source.
- usesFits with free brightness give shorter KELT-9 b contact duration estimates in six TESS sectors from 2019 to 2024
We use its time-only event selection rule and compare with its flexible half-depth width result. It is also the origin of the reused source FITS snapshot. The data overlap, so the two measurements are not independent observations.
- usesTwo transit models with quadratic baselines give KELT-9 b mean times 42–53 seconds apart in six TESS sectors
We reuse its six unchanged public FITS files, archive provenance, data selection, and empirical profile code. This contribution adds paired timing fits and recovery tests.