A free cadence phase fit keeps 18.5 to 37.1 percent of alias timing information in ten Kepler designs with independent errors
A correction for the exposure schedule can resemble a real transit timing signal. We measure this conflict in ten selected Kepler observing designs. The data contain 4,632 retained expected transit times, catalog errors, and time stamps from 168 long-cadence files. We compare a linear ephemeris correction with a joint fit that also has a free sine and cosine of recorded exposure phase. At each nominal cadence alias, the joint fit keeps 18.5 to 37.1 percent of squared signal-to-noise over all physical phases. The largest same-phase amplitude increase is 1.70 to 2.33 within each object. A constant-clock control keeps almost no information. The recorded time variation thus breaks the exact alias degeneracy but leaves a large information loss. At both tested offsets of one inverse observing span, all ten designs keep at least 96.9 percent. The package gives information matrices at 12,010 object-frequency pairs, code, source data, figures, and repeat instructions. All 168 original files pass the source audit. Direct least-squares checks and 20,000 Gaussian trials per object support the calculation. These are conditional design results with independent known catalog errors. They do not identify a measured signal's cause or establish a new planet. The sample is fixed and is not representative of all Kepler targets.
Kepler · transit timing · cadence alias · information loss · observing design · signal detection · reproducible research
References
6- usesRecorded cadence phase gave a 0.998 geometric mean timing error ratio against lines in ten selected Kepler objects sci:sha256:20bc51c320155c9533a11e0b6381b2347dd99af847c1727591dc3fb0fa46d330
We use its fixed ten-object Kepler sample, exact Holczer table 3, cadence time extracts, and source provenance. We verify its signed archive. We ask a new design question and do not reproduce its later-time prediction result.
- usesdoi:10.3847/0067-0049/225/1/9
Table 3 supplies expected transit times, timing errors, integer epochs, and selection flags. Measured offsets enter only a finite-value check. The catalog and its treatment of sampling signals are prior work.
- usesdoi:10.17909/T9488N
Kepler long-cadence mission files supply the recorded time stamps and cadence numbers. The supporting package preserves all source URLs and hashes. All 168 original files pass a separate source audit.
- doi:10.1051/0004-6361/201220132
This work identified stroboscopic timing bias and the fifteen possible sampling cases from which the parent study selected ten. The sampling effect is established prior work.
- doi:10.1093/mnras/stt105
This work showed that barycentric time variation can separate Kepler sampling aliases. We do not claim that principle as new. We measure the remaining conditional timing information in ten real designs.
- A free BERV term removes over 99.9% of annual circular signal information at some phases in 151 HARPS designs under white noise sci:sha256:4f2be1c5e46742f40b4598bf5427841e077428f6d351fc726285900bc213d5ad
This earlier study used weighted information ratios to test a free nuisance term in HARPS schedules. We apply the same established projection principle to Kepler cadence phase. No data or code from that study are used.
Cited by
4 publicationsPublic catalog entries on Sciscape.
- An exposure phase error model increased mean later log loss in nine screened Kepler timing records
It calculates alias information loss under independent reported errors in the same ten designs. This study tests observed contrast error forecasts.
- At 170 GJ 3378 SPIRou times, five weight models limit 21.45 day sine signal transfer to a fixed 24.73 day two harmonic fit below 27%
Method precedent for exact weighted projection bounds over phase. We reuse no data or code.
- A Q2 profile reduced timing scatter across 30 averaging origins in 38 Q3 Kepler-13 b transits
This prior study measured conditional alias information and identified the need for flux-level tests. Our result tests two specific timing estimators with observed transit flux.
- An early exposure phase pattern repeats in nine later Kepler-13 b quarters after local trends are removed
Its design test shows that a free cadence phase fit can remove real alias-frequency signal information. This limits a causal interpretation of our measured phase association.