K5 residual images and matched F1 training gap

Current-generation five-fold A3 models · inspected 2026-10-04 · no new fitting

Conclusion: F1 has a visible brightness-dependent held-out training gap on the same pixels. Fainter bins retain common residual structure even where the ratio is near one. These conditional comparisons do not isolate a unique cause or establish improved photometry.

Full methods, equations and provenance · Inspection manifest: all 60 grid PNGs · Shared residual-grid page: 30 K5 tabs published · Parent crossfit directory

Catalogue TSourcesMedian paired OOF/in-training
8-91966.006
9-104272.309
10-119301.392
11-1229241.006
12-1360591.004

The comparator is each source’s median c² from the other four fold models, all evaluated on the same unmodified scene. c² is the mean standardized squared core residual; no degrees-of-freedom correction. Fluxes and nuisance prior calibration are conditional on the evaluation scene.

Same stars, native core pixels, common held-out flux denominator. All four in-training residual stacks remain separate. Integer-centre alignment smears subpixel phase. Signed stacks can cancel.
Same stars, native core pixels, common held-out flux denominator. All four in-training residual stacks remain separate. Integer-centre alignment smears subpixel phase. Signed stacks can cancel.
Each fold shows a bright-source training gap. Fold spread is descriptive, not a confidence interval; a ratio near one does not validate the residual/noise model.
Each fold shows a bright-source training gap. Fold spread is descriptive, not a confidence interval; a ratio near one does not validate the residual/noise model.
Two T 8–9 sources per fold selected by median and 90th-percentile score gap, not morphology. Opposing-sign core residuals are visible. Shared scale per row; data has its own scale.
Two T 8–9 sources per fold selected by median and 90th-percentile score gap, not morphology. Opposing-sign core residuals are visible. Shared scale per row; data has its own scale.

All 196 F1 catalogue-T 8–9 sources

Select any source. Native residuals use exactly the same physical core mask and held-out flux denominator for every model. The residual colour scale is shared across the selected source’s six panels; outside-core pixels are white. Red is positive, blue negative; data uses grayscale. No recentering or interpolation.

Measured data and all five full scene models

All six panels share one grayscale intensity range. Only originally valid pixels are shown.

F1: standard compatibility grids

Absolute grids retain positive central cores in many blue/mid-colour faint bins and asymmetric red-bin residuals, strongest toward the right and lower CCD cells. Relative grids remove much of the common blue/mid-colour structure but retain red-bin asymmetry. Fold panels repeat the populated-cell patterns with substantial sparse-bin sampling stripes.

Display bins: Gaia BP−RP and fitted-flux-derived TESS magnitude, not catalogue T / fitted XP u. The relative grid subtracts each cell’s all-star stack. Colour limits vary between images; sparse or blank bins are not null detections.

OOF: inspected absolute and relative gridsF1 OOF absolute residual gridF1 OOF relative residual grid
fold0: inspected absolute and relative gridsF1 fold0 absolute residual gridF1 fold0 relative residual grid
fold1: inspected absolute and relative gridsF1 fold1 absolute residual gridF1 fold1 relative residual grid
fold2: inspected absolute and relative gridsF1 fold2 absolute residual gridF1 fold2 relative residual grid
fold3: inspected absolute and relative gridsF1 fold3 absolute residual gridF1 fold3 relative residual grid
fold4: inspected absolute and relative gridsF1 fold4 absolute residual gridF1 fold4 relative residual grid

F2: standard compatibility grids

The pooled grid shows spatially varying blue-bin dipoles, stronger red-bin core structure, and relatively quiet mid-colour bins after cell-mean subtraction. Red upper-left and lower-left cells retain strong opposing lobes. Individual folds contain many empty bright-colour cells and striped/checkerboard sampling; they are not featureless residuals.

Display bins: Gaia BP−RP and fitted-flux-derived TESS magnitude, not catalogue T / fitted XP u. The relative grid subtracts each cell’s all-star stack. Colour limits vary between images; sparse or blank bins are not null detections.

OOF: inspected absolute and relative gridsF2 OOF absolute residual gridF2 OOF relative residual grid
fold0: inspected absolute and relative gridsF2 fold0 absolute residual gridF2 fold0 relative residual grid
fold1: inspected absolute and relative gridsF2 fold1 absolute residual gridF2 fold1 relative residual grid
fold2: inspected absolute and relative gridsF2 fold2 absolute residual gridF2 fold2 relative residual grid
fold3: inspected absolute and relative gridsF2 fold3 absolute residual gridF2 fold3 relative residual grid
fold4: inspected absolute and relative gridsF2 fold4 absolute residual gridF2 fold4 relative residual grid

S22: standard compatibility grids

The pooled grid has structured red-bin cores and a broad positive surrounding component in the middle-right CCD cell, alongside negative blue cores in some bright bins. The relative view removes part of the shared surrounding signal but preserves colour-dependent lobes. Folds show variable sampling stripes and blank bright bins; no unique single residual mode is established.

Display bins: Gaia BP−RP and fitted-flux-derived TESS magnitude, not catalogue T / fitted XP u. The relative grid subtracts each cell’s all-star stack. Colour limits vary between images; sparse or blank bins are not null detections.

OOF: inspected absolute and relative gridsS22 OOF absolute residual gridS22 OOF relative residual grid
fold0: inspected absolute and relative gridsS22 fold0 absolute residual gridS22 fold0 relative residual grid
fold1: inspected absolute and relative gridsS22 fold1 absolute residual gridS22 fold1 relative residual grid
fold2: inspected absolute and relative gridsS22 fold2 absolute residual gridS22 fold2 relative residual grid
fold3: inspected absolute and relative gridsS22 fold3 absolute residual gridS22 fold3 relative residual grid
fold4: inspected absolute and relative gridsS22 fold4 absolute residual gridS22 fold4 relative residual grid

C1: standard compatibility grids

The pooled absolute grid has central positive faint blue/mid-colour residuals and red-bin asymmetric cores across the CCD; the lower-right red cell is especially structured. Relative subtraction suppresses much of the mid-colour common component. Single-fold red bins and bright cells are often sparsely sampled, with striped patterns or missing images.

Display bins: Gaia BP−RP and fitted-flux-derived TESS magnitude, not catalogue T / fitted XP u. The relative grid subtracts each cell’s all-star stack. Colour limits vary between images; sparse or blank bins are not null detections.

OOF: inspected absolute and relative gridsC1 OOF absolute residual gridC1 OOF relative residual grid
fold0: inspected absolute and relative gridsC1 fold0 absolute residual gridC1 fold0 relative residual grid
fold1: inspected absolute and relative gridsC1 fold1 absolute residual gridC1 fold1 relative residual grid
fold2: inspected absolute and relative gridsC1 fold2 absolute residual gridC1 fold2 relative residual grid
fold3: inspected absolute and relative gridsC1 fold3 absolute residual gridC1 fold3 relative residual grid
fold4: inspected absolute and relative gridsC1 fold4 absolute residual gridC1 fold4 relative residual grid

C4: standard compatibility grids

Pooled bright blue residuals often have a negative core and positive surrounding region; red bins show a positive or asymmetric core with negative surrounding structure. The red/blue distinction persists after cell-mean subtraction. More populous faint bins are visually smoother than many single-fold bright bins. One negative-flux source remains in the primary score cohort but is excluded from these flux-normalized grids.

Display bins: Gaia BP−RP and fitted-flux-derived TESS magnitude, not catalogue T / fitted XP u. The relative grid subtracts each cell’s all-star stack. Colour limits vary between images; sparse or blank bins are not null detections.

OOF: inspected absolute and relative gridsC4 OOF absolute residual gridC4 OOF relative residual grid
fold0: inspected absolute and relative gridsC4 fold0 absolute residual gridC4 fold0 relative residual grid
fold1: inspected absolute and relative gridsC4 fold1 absolute residual gridC4 fold1 relative residual grid
fold2: inspected absolute and relative gridsC4 fold2 absolute residual gridC4 fold2 relative residual grid
fold3: inspected absolute and relative gridsC4 fold3 absolute residual gridC4 fold3 relative residual grid
fold4: inspected absolute and relative gridsC4 fold4 absolute residual gridC4 fold4 relative residual grid

C4 retained negative-flux exception

Fold 4, scene row 11902, Gaia 1436295372260016000, catalogue T=12.461, fitted source flux −155.7 e−/s. Retained in primary fixed-cohort c² metrics; excluded only from the positive-flux-normalized compatibility raster. The crowded native stamp includes masked pixels and opposing-sign core residuals; no unique cause is diagnosed here.

C4 negative-flux retained source data, full scene model and residual

Supported conclusion and limits

The matched images support the F1 bright training gap. All five fields retain colour/spatial residual structure. Spatial training coverage, nuisance amplitude fitting, and field/model uncertainty differ; this is not a one-factor overfitting experiment. These single-image figures do not establish calibrated noise, temporal accuracy, or better photometry. Independent-start and confirmation-image controls are evaluated elsewhere in the parent investigation.