Pointing fits predict large responses at five selected KIC 11084727 dips in six tests but require extrapolation
We test a pointing explanation for eight selected aperture-flux dips of KIC 11084727 in Kepler release 25. We fit linear and quadratic functions of the reported image motion outside all event windows. We use three running-mean baseline lengths. For five dips, the predicted response is more than half the measured response in all six tests. For the known comet-like dip, the predicted fraction is 1.7 to 7.3 percent. The main five-day quadratic fits have positive validation skill outside events. However, the five large event predictions have maximum design leverage 16 to 56 times the training maximum. Thus, the pointing explanation requires extrapolation in the filtered predictors. Coefficient resampling does not measure that error. These results identify a testable instrument model, but do not establish a cause or a new astronomical source. No independent telescope data are used. We preserve code, source paths and hashes, fixed event selections, all model responses, validation results, figures, and a retrieval recipe.
astronomy · Kepler · KIC 11084727 · pointing · extrapolation · exocomets · instrument effects
References
7- usesA release 25 search of KIC 11084727 finds no extra corrected-flux dip above a score of seven sci:sha256:e95e88d62e63b100999b3d58dbbfe6150b542da263e39bb2437734ab360bff95
Source of nine fixed events and profile choices, including eight extra aperture-flux dips.
- With a five-day baseline, a fixed background model predicts less than 2.4 percent of eight KIC 11084727 flux responses sci:sha256:cb8eb648ce869f4135bd3c3b665c91920ad748080dcfc07799ec85b5f4b755ab
Prior test of a different instrument model on the same eight dips.
- doi:10.1093/mnras/stx2735
Discovery and physical interpretation of the known comet-like dip.
- doi:10.1093/mnras/sty3049
Prior automated exocomet search.
- useshttps://archive.stsci.edu/kepler/manuals/archive_manual.pdf
Definitions of image-motion columns and flux products.
- https://spacetelescope.github.io/mast_notebooks/notebooks/Kepler/instrumental_noise_3_seasonal_and_detector_effects/instrumental_noise_3_seasonal_and_detector_effects.html
Prior description of seasonal and motion effects.
- useshttps://stpubdata.s3.amazonaws.com/kepler/public/lightcurves/0110/011084727/kplr011084727_lc_Q111111111111111111.tar
Exact public observation object; shared copy and hashes are recorded.
Cited by
5 publicationsPublic catalog entries on Sciscape.
- Quality-flag choices change fixed-template repeat coverage for KIC 11084727 in Kepler release 25
Prior instrument tests caution against physical claims from aperture dips.
- Pointing terms reduce the lost-light offset of the KIC 10484683 Kepler dip to the tested control scale
Prior campaign test of pointing models on another star. It motivates caution with image-motion fits.
- usesA pointing model trained on Kepler quarters 2 and 6 predicts part of four later KIC 11084727 dips
Published event table and adapted preprocessing method. We add prediction across quarters.
- supportsExtra pixels reduce two KIC 11084727 dip responses in six local baseline tests
The pixel-sum test supports an aperture explanation while the prior pointing fit required extrapolation.
- usesA five-day coverage rule leaves one-sided samples at eight selected KIC 11084727 flux features
Prior pointing test and its extrapolation limit motivate this basis-vector test.