Long GRB 260808A detected by Fermi GBM and multiple space instruments

AI Summary

Fermi GBM triggered on a long-duration gamma-ray burst (GRB 260808A) on 2026-08-08 at 02:51:42.31 UTC, localized to RA=341.8°, Dec=14.1° with 2.2° statistical uncertainty. The burst was independently confirmed by SVOM/GRM (T90=21±2 s), GECAM-B (T90=14±2 s), CALET/CGBM (T90=13.4±0.9 s), and NuSTAR, showing a multi-peaked structure consistent across instruments. Spectral analysis by SVOM/GRM revealed a power-law spectrum with exponential high-energy cutoff (photon index -1.16), typical of cosmological GRBs.

Measurements

Notices (1)

Fermi GBM — GRB · Sat, 08 Aug 2026 02:51:42 GMT

GCN Circulars (7)

GCN-45369 — GRB 260808A · Thu, 13 Aug 2026 03:20:24 GMT
The SVOM/GRM instrument detected GRB 260808A, a gamma-ray burst with multiple pulses and a duration (T90) of 21 ± 2 seconds. The burst was also observed by multiple other instruments, including Fermi/GBM, NuSTAR, CGBM, and GECAM-B, and its spectrum was best fitted by a power law function with an exponential high-energy cutoff.

GCN-45356 — GRB 260808A · Tue, 11 Aug 2026 10:49:01 GMT
The GECAM-B satellite detected a gamma-ray burst (GRB 260808A) on August 8, 2026, at 02:51:45.500 UTC, which was also observed by Fermi/GBM, NuSTAR, and CGBM. The burst lasted approximately 14 seconds and consisted of multiple pulses.

GCN-45347 — GRB 260808A · Mon, 10 Aug 2026 13:51:56 GMT
The CALET Gamma-ray Burst Monitor detected GRB 260808A on August 8, 2026, at 02:51:52.41 UTC. The burst, also reported by Fermi GBM and NuSTAR, showed a multi-peaked structure lasting approximately 15 seconds, with T90 and T50 durations of 13.4 and 7.1 seconds respectively.

GCN-45327 — GRB 260808A · Sun, 09 Aug 2026 07:43:36 GMT
The NuSTAR SINGS working group detected prompt emission from the long-duration GRB 260808A, with a peak count rate of approximately 1500 counts per second lasting about 20 seconds. The event was also detected by Fermi-GBM, and detailed analysis and lightcurves are available online.

GCN-45315 — GRB 260808A · Sat, 08 Aug 2026 06:09:23 GMT
A gamma-ray burst, designated GRB 260808A, was detected by the Fermi Gamma-ray Burst Monitor (GBM) on August 8, 2026. The event was localized using the BALROG algorithm, with a best-fit position at RA(2000.0) = 344.1 deg and Decl.(2000.0) = 11.9 deg, and an estimated error radius of 2.9 degrees plus an additional systematic error of 1 degree.

GCN-45314 — GRB 260808A · Sat, 08 Aug 2026 04:46:20 GMT
The MASTER-OAFA robotic telescope in Argentina began observing the error box of Fermi GRB 260808A 99 seconds after the alert, with an upper limit magnitude of 19.2. The observations were conducted under specific galactic coordinates and atmospheric conditions, with no optical transient detected.

GCN-45313 — GRB 260808A · Sat, 08 Aug 2026 03:02:15 GMT
The Fermi Gamma-ray Burst Monitor (GBM) detected a likely long gamma-ray burst (GRB 260808A) on August 8, 2026, at 02:51:42 UT. The event was located at RA = 341.8, Dec = 14.1 (J2000) with a statistical uncertainty of 2.2 degrees, and the angle from the Fermi LAT boresight was 72.0 degrees.