GCN Circular 41565
Subject
GRB 250827A: Fermi GBM Final Real-time Localization
Event
Date
2025-08-27T15:45:24Z (a month ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
Via
email
The Fermi GBM team reports the detection of a likely LONG GRB
At 15:34:53 UT on 27 Aug 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250827A (trigger 778001698.2092 / 250827649).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 346.8, Dec = -43.8 (J2000 degrees, equivalent to J2000 23h 07m, -43d 47'), with a statistical uncertainty of 7.2 degrees.
The angle from the Fermi LAT boresight is 90.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250827649/quicklook/glg_skymap_all_bn250827649.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250827649/quicklook/glg_healpix_all_bn250827649.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250827649/quicklook/glg_lc_medres34_bn250827649.gif