GCN Circular 39748
Subject
GRB 250317A: Fermi GBM Final Real-time Localization
Date
2025-03-17T00:16:07Z (19 days 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 00:05:29 UT on 17 Mar 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250317A (trigger 763862734.52183 / 250317004).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 148.2, Dec = -25.4 (J2000 degrees, equivalent to J2000 09h 52m, -25d 23'), with a statistical uncertainty of 6.3 degrees.
The angle from the Fermi LAT boresight is 23.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250317004/quicklook/glg_skymap_all_bn250317004.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/bn250317004/quicklook/glg_healpix_all_bn250317004.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250317004/quicklook/glg_lc_medres34_bn250317004.gif