Long GRB 260709A detected by Fermi GBM and confirmed by multiple satellites

AI Summary

Fermi GBM detected a long-duration gamma-ray burst (GRB 260709A) on 2026-07-09 at 01:07:32 UT, localized to RA=84.1°, Dec=74.0° with 4.0° uncertainty. The burst was independently confirmed by GECAM-B (T90~56s, fluence 1.5e-05 erg/cm²), SVOM/GRM (T90~63s, fluence 3.0e-05 erg/cm²), and the Avion cubesat (T90~18s, fluence 4.5e-07 erg/cm²), with spectral analysis showing power-law indices around -2.4 to -2.9. Multi-instrument detection and consistent temporal/spectral properties confirm this as a genuine astrophysical long GRB.

Measurements

Notices (1)

Fermi GBM — GRB · Thu, 09 Jul 2026 01:07:32 GMT

GCN Circulars (4)

GCN-45297 — GRB 260709A · Thu, 06 Aug 2026 08:49:20 GMT
The long-duration gamma-ray burst GRB 260709A was detected by the cubesat Avion of the Moscow University project “Sozvezdie-270” on July 9, 2026, with a total duration of approximately 18 seconds and a fluence of ~4.5*10^(-7) erg/cm^2 in the 40-500 keV range. This detection highlights the capability of small satellites in contributing to gamma-ray burst research.

GCN-45137 — GRB 260709A · Sat, 11 Jul 2026 05:58:51 GMT
The SVOM/GRM detected GRB 260709A on July 9, 2026, at 01:07:50.900 GMT, which was also observed by Fermi/GBM. The burst consisted of multiple pulses with a T90 duration of 63 seconds in the 15-5000 keV band, and its position was outside the SVOM ECLAIRs field of view.

GCN-45136 — GRB 260709A · Sat, 11 Jul 2026 05:57:32 GMT
The GECAM-B satellite detected a gamma-ray burst, GRB 260709A, on July 9, 2026, at 01:07:32 UTC, which was also observed by Fermi/GBM. The burst lasted approximately 56 seconds and had a power law index of -2.38, with a fluence of 1.5e-05 erg/cm^2 in the 10-1000 keV range.

GCN-45121 — GRB 260709A · Thu, 09 Jul 2026 01:18:22 GMT
The Fermi Gamma-ray Burst Monitor (GBM) detected a likely long gamma-ray burst (GRB 260709A) on July 9, 2026, at 01:07:32 UT. The event was located at RA = 84.1, Dec = 74.0 (J2000) with a statistical uncertainty of 4.0 degrees, and it was 106.0 degrees from the Fermi LAT boresight.