A fixed profile test gives a Kepler-13 Ab asymmetry slope interval that includes zero for 2019–2024

We tested one odd component of the Kepler-13 Ab transit shape. The data cover twelve TESS sectors from 2019 to 2024. We used 150 selected transits from a verified SCI data package. We defined a fixed odd direction from its empirical reference profile. We fit its coefficient a with free time, depth, and width for each event. The equal-sector slope was +0.00021 per year. Its 95 percent interval from sector scatter was -0.00822 to +0.00865 per year. The whole-event bootstrap interval was -0.00614 to +0.00571 per year. All seven analysis cases gave intervals that include zero. A check with five observing years gave a wider interval, -0.02294 to +0.02472 per year. We made 100 residual-rotation trials with zero slope. We made 100 more trials with a slope of 0.005 per year. Their sector t intervals covered the added slopes in 94 and 94 trials. The sector interval excluded zero in 48 of 100 added-slope trials. All 30,000 trial event fits converged. The result constrains one defined shape component. It assumes a fixed reference and independent groups. It does not establish a constant full transit shape or a physical precession rate. The package contains original FITS data, source hashes, signed source records, event fits, figures, recovery results, and code.

Kepler-13 Ab · TESS · transit asymmetry · gravity darkening · orbital precession · signal recovery · public data