Run date: 2026-09-24 UTC Campaign type: bounded software/recovery validation, not a novelty search Evidence classification: established target used as a validation case; this run itself is not a new candidate assessment.
Executive result#
A single MAST TESS SPOC 2-minute light curve for TIC 86396382 (WASP-12) was searched with a box least-squares (BLS) periodogram. The strongest grid peak is at 1.0914183 d. Its fitted box has a 2.448 h duration and 1.4228% depth (14,228 ppm) in PDC-SAP flux. The feature is also present at the same ephemeris in SAP flux: BLS power 0.1500 and depth 1.3987%, versus 0.1551 and 1.4228% for PDC-SAP. This successful recovery of the well-known transiting system is a useful smoke test of the retrieval and basic extraction, not a discovery.
There were 18,954 light-curve rows; 16,551 finite, positive-flux, quality-zero cadences were analyzed. The data span 26.318 days. Timestamps are BTJD = BJD − 2457000, with TIMESYS=TDB; the FITS header gives 120-second cadence. The recovered grid period agrees with the expected approximately 1.09-day WASP-12 b signal, but this campaign did not perform a literature/ephemeris fit or refine the period.
Ranked leads#
| Rank | Target / product | Result | Evidence level | Main concern | Next test |
|---|---|---|---|---|---|
| Validation only | WASP-12 / TIC 86396382; TESS Sector 20; tess2019357164649-s0020-0000000086396382-0165-s_lc.fits | BLS P=1.0914183 d, duration=2.448 h, depth=1.4228%; SAP independently retains a similar box at this fitted ephemeris | Known-object recovery; not a candidate | One sector; no pixel-level or pointing/systematics audit; simplistic permutation null | Repeat at another TESS epoch and carry out centroid/difference-image, detrending, and calibrated injection/recovery tests |
No other targets were screened; there are no rejected astrophysical leads to rank. This tiny campaign makes no claim of completeness.
Data provenance and reduction#
- Archive/release: Mikulski Archive for Space Telescopes (MAST), TESS SPOC light curve, Sector 20, 120-s cadence.
- Product ID:
tess2019357164649-s0020-0000000086396382-0165-s_lc.fits. - Product URL: MAST file download.
- Selection provenance: existing Tier-1 manifest records a TESS/SPOC timeseries cone selection around TIC 86396382, radius 0.05 degree, product subgroup LC. Product re-downloaded 2026-09-24 UTC into the configured scratch area; no bulk data retained in this report folder.
- Coordinates: FITS
RA_OBJ=97.6366528 deg,DEC_OBJ=+29.6722962 deg; these are product-header coordinates. No epoch propagation or independent astrometric match was needed/performed. - Checksum: observed SHA-256
bf74a16f6e0c40b693a66de922e142d446cb44cee5bb7f26843062e436957f63, exactly matchingdocs/tier1_pack/MASTER_MANIFEST.csv. - Time standard: FITS extension reports
TIMESYS=TDB,BJDREFI=2457000,BJDREFF=0;TIMEvalues below are therefore BTJD. Usable timestamp range is 1842.509510–1868.827130 BTJD (baseline 26.317620 d). - Flux and filters: used
PDCSAP_FLUX, requiring finite positive flux andQUALITY == 0; excluded 2,403 rows from 18,954 on those combined criteria. Normalized by the median of retained flux. No additional outlier clipping or detrending was applied. SAP flux was median-normalized and checked at the PDC best-fit period/duration.
Search and measurements#
BLS was evaluated using Astropy BoxLeastSquares, likelihood objective, 5,000 linearly spaced trial periods from 0.5 through 5.0 d and six trial durations from 0.06 through 0.16 d. The maximum was at P=1.0914182837 d and transit epoch BTJD 1843.0045102. The grid period spacing is about 0.0009002 d (about 78 s), so the quoted period is only a coarse grid estimate. The epoch is the fitted periodic-box reference in BTJD, not a precision transit-time measurement. Fitted depth is 0.0142284 in normalized PDC-SAP flux; the reported BLS power is 0.15507 (algorithm objective, not a sigma).
A seeded permutation diagnostic shuffled the retained flux values relative to the observed timestamps 20 times and recorded each shuffled series' maximum over the same BLS search. None of the 20 null maxima reached the observed power; the 95th percentile of null maxima was 0.0003795. With the add-one estimator this is reported as 1/21 = 0.0476, which mostly reflects the coarse 20-trial Monte Carlo floor. It is not a calibrated false-alarm probability: shuffling destroys time-correlated stellar/instrumental noise, and 20 trials are inadequate for a tail estimate. Do not interpret it as astrophysical significance.
Artifact audit / limitations#
| Test | State | Result / limitation |
|---|---|---|
| Product integrity | passed | SHA-256 matches the existing manifest. |
| Cadence quality mask and finite-flux selection | passed | Exact selection and row counts recorded above. Quality flags were not individually decoded. |
| PDC versus SAP persistence | partial diagnostic | Comparable depth and BLS power at the PDC ephemeris; useful but not an independent reduction or pixel-level validation. |
| Alternative detrending/aperture | not tested | No custom detrending, aperture photometry, or extraction comparison. |
| Transit centroid / difference image / blend audit | not tested | No pixel-level data analyzed. |
| Pointing/centroid-jitter correlation | not tested | No engineering/centroid vectors inspected. |
| Red-noise-aware null or search-wide calibrated FAP | not tested | Permutation null is deliberately labeled inadequate above. |
| Independent epoch/instrument | not tested | One sector only. |
| Catalog/literature audit | not performed in this run | Target was chosen as a known-planet recovery test; no novelty inference is made. |
Accordingly, this is a positive pipeline smoke test, not a vetted candidate dossier. Reproducibly recovering a known signal does not demonstrate completeness, reliability against all artifacts, or sensitivity to isolated/nonperiodic transits.
Reproduction and artifacts#
From the worktree root, with the project science environment installed:
& '[private path]' campaigns\run_wasp12_sector20.pyThe script reuses the cached scratch FITS file if present, otherwise fetches the exact public MAST product; it fails closed if the SHA-256 differs. It writes machine-readable output to campaigns/wasp12_sector20/results.json. The scratch FITS is disposable under the existing worktree policy and is not a deliverable. The code records the random seed (20260925), search bounds, grid, masks, checksum, and software versions. Runtime environment observed: Python 3.13.3, NumPy 2.5.3, Astropy 8.0.1 (the script uses Astropy BLS/FITS); SciPy was present but not used. No unit test suite for this campaign-specific analysis was added; the run itself and checksum are the validation record.
Recommended follow-up#
- Repeat the exact BLS and transit-window check on another, temporally separated SPOC sector for TIC 86396382; compare depth/shape while accounting for dilution and stellar variability.
- Run a calibrated local injection/recovery grid in this light curve, including transit-like signals across periods/durations and realistic correlated noise; report completeness rather than relying on this single successful recovery.
- Inspect pixel-level products and difference-image centroids, and compare SAP/PDC and at least one alternate detrending recipe before using this workflow on unknown targets.
- For an actual discovery campaign, freeze a target pool and selection before viewing results, pin known-object watchlists, establish a null population, and record all exclusions/rejections.
Addendum (2026-09-24, later): ledgered re-run#
Re-run through the campaign runner (python -m cygnus.campaign run campaigns/wasp12-sector20-recovery.yaml; ledger runs #35–#37) with the same seed (20260925) and environment. results.json is identical to the original except its run timestamp. The catalogue cross-match found WASP-12 b (NASA Exoplanet Archive), TOI-1725.01 (disposition KP), the VSX entry and the SIMBAD system, as expected for a known-planet test; results are in the ledger prior_art table.