Overview
- GRB 250702B is confirmed as the longest gamma‑ray burst on record, with activity lasting nearly seven hours and a dust‑obscured afterglow traced to a massive galaxy billions of light‑years away.
- Coordinated observations across Fermi and Swift in space plus VLT, Gemini, Keck, Hubble, Blanco and other facilities on the ground captured the burst’s afterglow and host environment.
- Anomalous behavior for GRB 250702B — including early X‑ray activity, prolonged flaring and no clear supernova — defies standard categories, prompting competing progenitor models under active study.
- Separately, JWST confirmed a supernova linked to GRB 250314A at redshift ~7.3, making it the earliest observed stellar explosion about 720–730 million years after the Big Bang.
- The GRB 250702B analysis appears in The Astrophysical Journal Letters, the GRB 250314A supernova results in Astronomy & Astrophysics, with additional JWST observations approved to investigate progenitors and host galaxies.