A local centroid model gives different flux-loss coefficients for two deep dips of KIC 8462852

We tested a local centroid model for the known D800 and D1520 dips of KIC 8462852 in Kepler quarters 8 and 16. The model uses the exact flux-loss factor L/(1-L). Four fits with pointing terms give coefficient magnitudes of 0.02770 to 0.02802 pixel for D800 and 0.00430 to 0.00448 pixel for D1520. Thus, one fixed measured coefficient does not describe both events under these choices. Removing the pointing terms changes the estimates. The result agrees in general with earlier work on variable centroid response. It does not show that the dips occur on different stars. The aperture masks differ, both quarters use channel 56, and all PSF centroid values are missing. Conditional noise intervals do not include all detector and baseline errors. We establish no new dip, planet, or source position. The package includes the two raw light curves, exact hashes, code, all fits, figures, and offline instructions.

Kepler · KIC 8462852 · centroid · flux loss · blending · method audit