DPR Institute: research notesIndependent research in physics, electronics, chemistry, astronomy, and sustainability. Questions, methods, data, code, and results from DPR Institute, a working name for Derifield Physical Sciences Research.https://dprinstitute.org/en-gbTwo real single-transit fits, and why they are not a timing resulthttps://dprinstitute.org/notes/2026/two-real-single-transit-fits/https://dprinstitute.org/notes/2026/two-real-single-transit-fits/KELT-11 b and HD 209458 b fits with the published period fixed, plus the full-sector cross-check that disagrees at the formal precision.Sun, 25 Oct 2026 00:00:00 GMTexoplanetstransit-timinglight-curvesastronomy-methodsAperture diagnostics on the real sector 56 product sethttps://dprinstitute.org/notes/2026/aperture-diagnostics/https://dprinstitute.org/notes/2026/aperture-diagnostics/A threshold aperture run on the HD 209458 b target pixel file, compared with the mission SAP and PDCSAP columns on one common quality mask.Sat, 24 Oct 2026 00:00:00 GMTlight-curvesastronomy-methodsopen-scienceThe archive selection rule, and how 598 rows became 304 docket rowshttps://dprinstitute.org/notes/2026/archive-selection-rule/https://dprinstitute.org/notes/2026/archive-selection-rule/A fixed four-gate rule applied to a public confirmed-planet table, with the counts, the one-sided docket flag, and the limits recorded.Sat, 24 Oct 2026 00:00:00 GMTexoplanetstransit-timingastronomy-methodsOne real product set: HD 209458 b, sector 56https://dprinstitute.org/notes/2026/hd-209458b-sector-56/https://dprinstitute.org/notes/2026/hd-209458b-sector-56/The SPOC 120 s light curve and target pixel file for HD 209458 b, with archive URLs, byte counts, and SHA-256 digests. Acquisition record only.Sat, 24 Oct 2026 00:00:00 GMTexoplanetslight-curvesopen-scienceInjection-recovery: what twelve synthetic transits can and cannot showhttps://dprinstitute.org/notes/2026/injection-recovery/https://dprinstitute.org/notes/2026/injection-recovery/Twelve injected mid-transit times recovered on synthetic light curves. The timing bias is small against the pre-declared gate, but the sample is too small to calibrate a real pipeline.Sat, 24 Oct 2026 00:00:00 GMTtransit-timingastronomy-methodsreproducibilityA toy transit fit: what the trapezoid recovers on synthetic datahttps://dprinstitute.org/notes/2026/synthetic-transit-fit/https://dprinstitute.org/notes/2026/synthetic-transit-fit/A seeded synthetic light curve fitted with a trapezoid model. The recovered parameters agree with the injected values within about two reported sigma.Sat, 24 Oct 2026 00:00:00 GMTexoplanetstransit-timingscientific-computingWindow QC on the sector 56 light curvehttps://dprinstitute.org/notes/2026/window-qc/https://dprinstitute.org/notes/2026/window-qc/Cadence coverage, background, and centroid summaries for eight predicted transit windows in the HD 209458 b sector 56 light curve. Descriptive only.Sat, 24 Oct 2026 00:00:00 GMTlight-curvesastronomy-methodsreproducibility