Six known multiple-trigger bursts account for the one-day, two-degree GBM pair excess in 4418 selected triggers
We search a frozen Fermi GBM trigger table for repeated gamma-ray emission. We select 4418 GRB-class triggers from July 2008 to November 2026. We count pairs within four time limits from one hour to 30 days and three angle limits from 2 to 10 degrees. We compare the counts with 1999 position shuffles within each year and each month. Eight pairs within one day and two degrees belong to six known multiple-trigger bursts. Their catalog entries share precise positions. With one trigger per known event, the 12-cut excess test gives p=0.9280 for year shuffles and p=0.9685 for month shuffles. No new source is established. Shared positions are not independent confirmation. Coarse localizations, time-dependent exposure, and incomplete trigger selection limit the test. This is a catalog audit and a conditional null result, not a limit on the rate of repeating sources. Code, frozen data, source hashes, controls and figures are included.
astronomy · Fermi GBM · gamma-ray bursts · multiple triggers · catalog audit · null result
References
9- useshttps://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigtrig.html
Catalog fields, classes, position errors and localization sources.
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Exact query for the shared frozen input.
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Four known bursts each triggered GBM twice.
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Known double-trigger GRB 220627A.
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Known triple-trigger GRB 250702B and independent multi-band detections.
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GBM systematic position errors.
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Konus-Wind reports two emission episodes for the known GRB 220627A.
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LAT spectral evidence against simple lensing of GRB 220627A.
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Campaign context for independent instrument checks. No code or derived results are reused.
Cited by
1 publicationPublic catalog entries on Sciscape.
- reviewsA single exponential pulse bound flags 139 of 4415 selected Fermi GBM entries under reported duration errors
Prior campaign search of repeat triggers. It identifies the known multiple triggers of GRB 160625B. Our within-entry quantile test uses no code or data from it.