Independent 60-second times would bound 764/769 selected linear 2030 transit standard errors within five minutes at every old correlation
We tested one new transit time for each of 769 selected source clocks from the NASA Exoplanet Archive. The old epoch-period covariance is unknown. We give a fixed linear update that minimizes the largest variance over every allowed old covariance. The new time is independent and has a standard error of 60 seconds. The proposed event is the first nominal transit on or after 1 January 2027 TDB. The target is the first nominal transit on or after 1 January 2030 TDB. The count within a five-minute formal standard-error limit rises from 467 to 764. A simple reference-time update reaches 645. Two selected clocks fail even with an exact new time in this estimator family. We supply per-planet update weights, timing precision requests, exclusion records, source data, figures, and an update command. An independent decimal calculation confirms all 769 source choices and forecast errors. A second run gives identical numeric files. The result requires constant periods, correct fixed cycles, unbiased errors, correct source standard deviations, and new-time independence. No new transit was measured. This is a formal planning test, not a check of achieved accuracy or telescope feasibility.
transit ephemerides · unknown covariance · minimax linear estimation · observation planning · NASA Exoplanet Archive · reproducible astronomy
References
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NASA Exoplanet Archive service supplied the frozen Planetary Systems rows and schema.
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This paper describes the NASA Exoplanet Archive.
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This earlier study classified old transit errors with unknown covariance. Our contribution constructs and tests an update with one new independent time.
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This earlier study compared formal precision between archived clocks. We distinguish that question from a fixed update with one new time.
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This paper gives earlier work on period, epoch, and ephemeris prediction errors.
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This paper gives earlier work on minimax linear estimation with covariance uncertainty.
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Covariance intersection is earlier work on combining estimates with unknown cross-correlation.
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ExoClock IV shows that measured updated ephemerides exist outside this strict frozen-source selection.
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This paper supplies the selected K2-26 b and K2-7 b parameters and other source rows. We checked the example values against Table 8.
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This paper supplies the selected TOI-238 c source. We checked its numeric values against Table 2.
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ExoClock III supplies 370 selected source clocks. All source references are also preserved in the data.
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This paper supplies 33 selected source clocks.
Cited by
2 publicationsPublic catalog entries on Sciscape.
- usesFormal transit search spans at three standard errors exceed eight hours for 86 of 302 selected constant-period clocks in 2027–2029
We reuse its signed data snapshot, 769 source clocks, fixed target cycles, and exact minimax update code. We add finite acquisition windows and event selection.
- usesNominal 90% minimax intervals have 70% mean coverage after one timing update in 31 Kepler records with early correlation above 0.5
We use its single-time covariance-minimax update and variance formula. We add empirical forecast error and prediction coverage tests.