Overview
- GRB 250702B, detected on July 2, lasted nearly seven hours, setting a new duration record and defying standard gamma-ray burst models.
- Follow-up across Fermi, Hubble, VLT, Gemini, Keck, X-ray and radio facilities traced a heavily obscured afterglow to a distant, massive, dust-rich galaxy.
- Analyses indicate a narrow, ultra-relativistic jet pointed toward Earth with material moving at roughly 99% of light speed, yet no single progenitor fits all data.
- Published work in The Astrophysical Journal Letters outlines multiple possibilities—massive star collapse, exotic mergers, or tidal disruption scenarios including intermediate-mass black holes—without a definitive choice.
- Separately, JWST confirmed GRB 250314A as a supernova from about 730 million years after the Big Bang, establishing the most ancient supernova yet seen and demonstrating GRB-triggered studies of the early universe.