GRB 260307A

General information

GRB 260307A is reported as a likely long GRB, triggered by Fermi/GBM at 2026-03-07 11:27:59 UT and subsequently confirmed by several gamma-ray instruments (including CALET/CGBM, GECAM-B, Glowbug, and TERI). A GBM final localization is provided near RA=209.07 deg, Dec=29.03 deg (J2000) with a 2.88 deg statistical uncertainty.

Wavelength coverage

• Gamma-ray: Detected/characterized by Fermi/GBM, CALET/CGBM, GECAM-B, Glowbug, and TERI with reported multi-peaked prompt emission and durations of ~4.5–5 s.
• Optical: MASTER-Kislovodsk reports only upper limits (clear filter), reaching ~17.6 mag starting ~5.25e4 s after trigger. No observations are mentioned in X-ray, UV, IR, radio, or TeV.

Lightcurve and spectrum

Redshift

What’s special vs typical

The prompt emission is independently confirmed by an unusually large set of gamma-ray instruments, including multiple ISS-based technology demonstrators (Glowbug and TERI), with consistent reports of multi-peaked temporal structure.