GCN Circular 45712
GRB 260924A: Fermi GBM Final Real-time Localization
From: Fermi GBM Team at MSFC/Fermi-GBM
Issued: 2026-09-24 01:23 UTC
Why this event is posted: its fluence of 3.8×10^-4 erg/cm² is at or above this year's top-10% threshold of 3.9×10^-5, and it has drawn 28 GCN Circulars, at or above the top-10% threshold of 14.
The Fermi GBM team reports the detection of a likely LONG GRB
At 01:13:23 UT on 24 Sep 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260924A (trigger 811905208.561746 / 260924051).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 139.9, Dec = 9.7 (J2000 degrees, equivalent to J2000 09h 19m, 9d 41'), with a statistical uncertainty of 1.6 degrees.
The angle from the Fermi LAT boresight is 62.0 degrees.
The skymap can be found here:
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260924051/quicklook/glg_healpix_all_bn260924051.fit
The GBM light curve can be found here:
Filter: gamma-ray bursts are posted only if in the top 10% of the past year's — by fluence (total energy received per cm², from Fermi GBM, Konus-Wind, GECAM and similar circulars; now ≥ 3.9×10^-5 erg/cm²) or by the number of GCN Circulars about the burst (now ≥ 14). Thresholds are recalculated monthly.
Relayed automatically from NASA's General Coordinates Network.
GRB 260924A
The whole thread (28 posts)
- GRB 260924A
- GRB 260924A: VLA detection
- GRB 260924A: Swift/UVOT UV grism spectrum results
- GRB 260924A: AbAO optical observations
- GRB 260924A: Upper limits from a neutrino search with IceCube
- GRB 260924A: Near-infrared detection with MDM/MIRAGE
- GRB 260924A: COLIBRÍ optical observations
- GRB 260924A: Second-epoch J-band upper limit from the SYSU 80 cm infrared telescope
- Konus-Wind detection of GRB 260924A
- GRB 260924A: Extreme Isotropic-equivalent Gamma-ray Energy and encouragement for multiwavelength follow-up observations
- GRB 260924A: Optical follow-up observations with Kinder
- GRB 260924A: Ondrejov D50 optical afterglow detection
- GRB 260924A: SVOM/GRM observation
- GRB 260924A: 2.2m CAHA spectroscopic redshift z = 3.51
- GRB 260924A: J-band observations by the SYSU 80 cm infrared telescope
- GRB 260924A: Swift/UVOT Detection
- GRB 260924A: GROWTH-India Telescope optical observations
- GRB 260924A: Swift-BAT refined analysis
- GRB 260924A: NuSTAR detection of prompt emission
- GRB 260924A: Swift/UVOT Upper Limits
- GRB 260924A: Swift-XRT refined Analysis
- GRB 260924A: Fermi GRB Observation
- GRB 260924A: Fermi-LAT detection of a bright burst
- GRB 260924A: AstroSat CZTI detection
- GRB 260924A: NOT optical counterpart confirmation
- GRB 260924A: detection of a bright optical afterglow by the 1.5m OSN telescope
- GRB 260924A: Enhanced Swift-XRT position
- GRB 260924A: Swift detection of a burst