Overview
- In March 2026 the Einstein Probe detected a brief X-ray flash from a galaxy about 500 million light-years away that follow-up teams identified as EP260321a, later named SN 2026gzf, a broad-lined Type Ic supernova.
- Two independent research teams published peer-reviewed studies confirming the initial X-ray pulse was a shock breakout, only the second clear X-ray shock breakout seen in roughly 20 years.
- The measured shock breakout was the faintest yet associated with an Ic‑BL event, even though the supernova itself matched other energetic Ic‑BL explosions in optical and spectral properties.
- Coordinated X-ray, optical, infrared and radio observations found no evidence of a relativistic jet, afterglow, or gamma-ray burst, leading authors to propose a 'choked jet' blocked by the star’s surface or dense circumstellar shells.
- Archival and follow-up data map a Wolf–Rayet progenitor of about 20 solar masses that shed multiple shells before collapse, and teams will continue monitoring and hunting for more early shock-breakout captures to refine explosion and jet-formation models.