Fermi GBM trigger 795096033 retracted; likely not a genuine GRB

AI Summary

The Fermi Gamma-ray Burst Monitor detected trigger 795096033 on 2026-03-13 at 12:00:28.58 UT, initially classified as a long GRB with coordinates varying across multiple alerts (RA 53.4°/241.16°, Dec 33.3°/5.8°). However, the GBM team subsequently retracted the GRB classification, determining the trigger's nature to be uncertain and unlikely to represent a genuine gamma-ray burst. Ground-based follow-up observations by MASTER-Kislovodsk yielded only upper limits (mag 12.5-19.8), with no optical counterpart detected, further supporting the non-astrophysical origin of this event.

Measurements

Notices (1)

Fermi GBM — GRB · Fri, 13 Mar 2026 12:00:28 GMT

GCN Circulars (4)

GCN-44047 — GRB 260313A · Wed, 18 Mar 2026 15:31:39 GMT
The Fermi Gamma-ray Burst Monitor team has retracted their initial classification of GRB 260313A (trigger 795096033/260312500), which was previously identified as a gamma-ray burst on March 13, 2026. The nature of this trigger is now considered uncertain.

GCN-43998 — GRB 260313A · Sat, 14 Mar 2026 01:16:55 GMT
The MASTER-Kislovodsk robotic telescope in Russia began observing Fermi GRB 260313A 31381 seconds after the initial notice and 31405 seconds after the trigger time. The observations were carried out with upper limits ranging from 12.5 to 19.8 mag in the clear filter. The location of the GRB is at galactic latitude b = 39 deg., longitude l = 17 deg.

GCN-43995 — GRB 260313A · Fri, 13 Mar 2026 18:31:37 GMT
The Fermi Gamma-ray Burst Monitor Team has issued a correction to the initial localization of GRB 260313A, which occurred on March 13, 2026. The updated location is RA = 241.16, Dec = 5.80, with a statistical uncertainty of 5.8 degrees. The angle from the Fermi Large Area Telescope (LAT) boresight is 15 degrees. The corrected data can be accessed through various links provided.

GCN-43987 — GRB 260313A · Fri, 13 Mar 2026 12:11:03 GMT
The Fermi Gamma-ray Burst Monitor (GBM) has detected and located a long gamma-ray burst, GRB 260313A, at coordinates RA = 53.4, Dec = 33.3 (J2000) with a statistical uncertainty of 14.1 degrees. The angle from the Fermi Large Area Telescope (LAT) boresight is 152.0 degrees. The team at MSFC/Fermi-GBM has provided links to the skymap, HEALPix FITS file, and light curve for further analysis.