{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"1503ea1626570fff2ab798d085d287ff0b4268c6b20da9452de6fff37d6d62fd","created":"2026-10-03T07:17:55Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"7da7361bcf27129fec89301e338d0cfe6890bf4f050e68be26e05b01f06e1957","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"identification","assisted_by":[],"external_id":"astro.grb-engines-jets.grb-250702b","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"In July 2025 a gamma-ray source in a distant galaxy, seen as it was roughly 8 billion years ago, flared three times over several hours, unlike any known burst.","posed_since":"2025","precise":"GRB 250702B (host redshift estimated as $z \\sim 1$) showed three gamma-ray episodes over several hours, preceded by an X-ray transient detected by Einstein Probe about $10\\,\\mathrm{hours}$ earlier. Determine the engine: a relativistic tidal disruption of a star by an intermediate-mass black hole, an ultra-long collapsar with prolonged fall-back, or another channel. Answer: an identification whose energy budget and timescales fit the light curve, afterglow and host.","problem_ref":null,"references":"","settled_by":"A spectroscopic host redshift and late-time observations showing or excluding a supernova, combined with afterglow modeling and comparison to tidal-disruption fall-back rates.","status_note":"2025: JWST and ground-based imaging placed the source in a host galaxy at an estimated $z \\sim 1$; relativistic tidal disruption by an intermediate-mass black hole and an unusual collapsar remain the leading candidates.","title":"Nature of the repeating gamma-ray burst GRB 250702B","topic_ref":"d34ff2cb4f455ed6abcd7339be502ac934cb4f47f2fd2df51ba89febba9c8dd6"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"c90c7a54ce8b1c8dc10f0d094509ce8143fa3765da811294c31e5232efb44c89","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"f8f13e76c5a9f7c0fefd271d4b5ab0dcf4390ce5afccf34674b2a6632cd5eedd","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"l8YQQzYA8TnwCVuj9KiQeFfWDyr6fztBwt_RRQzJUx8uDSHXYArJFcx0hXfo4RCRdfDJ1rF0lhmg56-CGC1zBQ"},"schema":"pubphys.envelope/1"},"record_hash":"c90c7a54ce8b1c8dc10f0d094509ce8143fa3765da811294c31e5232efb44c89","leaf_index":546}