Overview

• Multiple teams report ~25,000 seconds of prompt gamma-ray emission, the longest on record, with a hard spectrum and subsecond variability indicative of an ultrarelativistic jet.
• Einstein Probe identified a soft X-ray precursor up to about a day before the gamma rays, and Swift, NuSTAR, and Chandra find steep X-ray decay and flaring consistent with a central engine active for at least three days.
• JWST NIRSpec spectroscopy measures z = 1.036 ± 0.004 and implies an isotropic-equivalent gamma-ray energy of ≥2.2 × 10^54 erg, with no bright accompanying supernova detected.
• Deep optical/IR follow-up shows a highly obscured afterglow and a massive (~10^10.66 M☉), dusty, asymmetric host consistent with a major merger, with the burst located off-nucleus.
• Proposed progenitors include a micro–tidal disruption by a stellar-mass compact object, a helium-star plus black-hole merger, and a white-dwarf stripping scenario by an intermediate-mass black hole, with one analysis reporting repeating triggers and possible periodicity and all calling for late-time X-ray and multiwavelength monitoring to discriminate models.