Fermi GBM detects and localizes GRB 260311B with a statistical uncertainty of 11.7 degrees.

AI Summary

The Fermi Gamma-ray Burst Monitor (GBM) detected a likely long-duration GRB 260311B on March 11, 2026, with a final real-time localization at RA = 278.5, Dec = 0.4. Follow-up observations by the MASTER-Kislovodsk robotic telescope provided upper limits ranging from 15.6 to 18.0 mag.

Notices (2)

Fermi — GRB · Wed, 11 Mar 2026 13:27:55 GMT

Unknown — OTHER · Wed, 11 Mar 2026 13:27:55 GMT

GCN Circulars (2)

GCN-43972 — GRB 260311B · Thu, 12 Mar 2026 12:32:31 GMT
The MASTER-Kislovodsk robotic telescope in Russia began observing Fermi GRB 260311B at a zenith distance of 57 degrees and obtained upper limits ranging from 15.6 to 18.0 mag in clear band for various observations. The telescope started inspecting the GRB 24516 seconds after the notice time and 24692 seconds after the trigger time.

GCN-43964 — GRB 260311B · Wed, 11 Mar 2026 19:08:31 GMT
The Fermi Gamma-ray Burst Monitor (GBM) has detected and localized a gamma-ray burst (GRB 260311B) at RA = 278.5, Dec = 0.4 (J2000 degrees) with a statistical uncertainty of 11.7 degrees. The angle from the Fermi Large Area Telescope (LAT) boresight is 54.0 degrees.