{"paper":{"title":"The ultra-long Gamma-Ray Burst 111209A: the collapse of a blue supergiant?","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"(10) University of Western Australia, (11) IAPS/INAF), 2), (2) Observatory of Rome/INAF, (3) University of Toulouse, 4, (4) Observatoire Midi Pyr\\'en\\'ee, 5, 5), (5) IRAP/CNRS, (6) University of Aix-Marseille, 7), (7) LAM/CNRS, (8) Artemis/CNRS, 9), 9) L. Piro (11) ((1) ASDC/INAF, (9) Observatory of Haute Provence/CNRS, A. Klotz (3, B. Gendre (1, D. M. Coward (10), E. Howell (10), G. Stratta (2), J.L. Atteia (3, M. Bo\\\"er (8, S. Basa (6, S. Cutini (1, V. D'Elia (1","submitted_at":"2012-12-11T11:51:51Z","abstract_excerpt":"We present optical, X-ray and gamma-ray observations of GRB 111209A, at a redshift of z = 0.677. We show that this event was active in its prompt phase for about 25000 seconds, making it the longest burst ever observed. This rare event could have been detected up to z ~ 1.4. Compared to other long GRBs, GRB 111209A is a clear outlier in the energy-fluence and duration plane. The high-energy prompt emission shows no sign of a strong black body component, as expected if the event was caused by a tidal disruption event or a supernova shock breakout. Given the extreme longevity of this event, and "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1212.2392","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}