General information
GRB 251211B is a likely long gamma-ray burst triggered by Fermi/GBM on 2025-12-11 20:32:04 UT and independently detected (faintly) by AstroSat CZTI. Early optical follow-up by MASTER-Net reported only upper limits.
Wavelength coverage
- Gamma-ray: Fermi/GBM trigger and localization; AstroSat CZTI veto detection in 100–500 keV.
- Optical: MASTER-Tunka clear-band imaging with limits to ~17.5 mag at ~629 s post-trigger.
No observations were mentioned for X-ray, UV, IR, radio, or TeV/GeV (LAT) bands.
Lightcurve and spectrum
Redshift
What’s special vs typical