Fitted KOI-2700b transit changes exceed control changes in Kepler Q1 to Q17 after windows with attitude tweaks are removed
We test whether the weak KOI-2700b transit signal changes between consecutive orbits. We analyze 17 public Kepler DR25 light curves. A fixed asymmetric profile and a local polynomial give paired amplitudes in transit windows and controls half an orbit later. We compare their mean squared changes after subtraction of formal noise. The initial 1,269 orbits give an excess of 61,543 ppm², with a wide 95% interval of -187,185 to 333,585 ppm². Two large Q2 terms coincide with recorded attitude tweaks and image motion. A rule added after this inspection removes complete windows with attitude tweaks. It retains 1,266 orbits and 1,104 consecutive pairs. Transit change power is then 64,572 ppm² and control change power is 19,477 ppm². The excess is 45,095 ppm². Its 95% interval is 20,456 to 69,795 ppm² for a bootstrap with 12-orbit blocks. Ten tested model settings retain positive lower bounds. Removal of any one quarter leaves a positive point estimate. Artificial signals and independent fits check the calculation. This exploratory result is evidence for excess changes in the fitted transit signal. Its physical interpretation requires the controls to represent residual noise in the transit windows. The intervals do not include the choice of the quality rule after inspection. The result does not establish a dust mechanism or confirm a new planet. The package preserves raw inputs, source hashes, code, all final tables, figures, and offline reproduction instructions.
KOI-2700b · KIC 8639908 · Kepler · transit variability · matched controls · attitude tweaks · structure function · public astronomical data
References
5- usesdoi:10.1088/0004-637X/784/1/40
The published asymmetric mean transit informed the fixed measuring profile. The earlier slow depth decrease is prior knowledge.
- usesdoi:10.1051/0004-6361/201629676
We use the published period of 0.9100259 days. The discussion of PDC correction informed the SAP choice.
- usesdoi:10.17909/T98304
The analysis uses 17 original DR25 long-cadence light curves for KIC 8639908 from this Kepler archive dataset.
- usesdoi:10.26133/NEA4
The cumulative KOI table retrieved on 2026-10-21 supplies the fixed epoch and a sensitivity-check period. The exact query and response are preserved.
- The previous transit reduced squared prediction error by 4.5% for 769 later Kepler-1520 b transits with fixed rotation terms sci:sha256:cd427b7f5b1d84facb3f5ebd783a1083d4369fe1a7c841705ef172b5422436e5
Related transit-change research on Kepler-1520b. The target and statistic differ. No code or results are reused.
Cited by
3 publicationsPublic catalog entries on Sciscape.
- usesThe primary Kepler Q1 to Q17 test leaves adjacent-orbit memory in KOI-2700 b uncertain under matched noise
We reuse its original FITS files, exact fixed-profile fitting code, coverage rules, and complete-window attitude veto. We recompute every fit. We add a separate covariance measurement and projected formal-noise correction.
- usesKepler Q1 to Q17 data give an approximate 95% lower transit fraction limit of 0.386 for KOI-2700 b under a fixed profile and unbiased fit errors
We use its rule to reject complete fitting windows with recorded attitude tweaks. It already measured rapid fitted transit changes. Our result instead bounds the fraction of orbits with the tested transit.
- usesA fixed window test leaves the KOI-2700 b tail to core ratio change uncertain in Kepler Q1 to Q16
We use its rule to remove whole fitting windows with recorded attitude tweaks. It studied rapid fitted amplitude changes, rather than our early-to-late window ratio.