GCN Circular 39597
Subject
GRB 250305A: Fermi GBM Final Real-time Localization
Date
2025-03-05T15:39:31Z (9 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 15:28:57 UT on 5 Mar 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250305A (trigger 762881342.919284 / 250305645).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 223.7, Dec = -3.0 (J2000 degrees, equivalent to J2000 14h 54m, -3d 00'), with a statistical uncertainty of 5.0 degrees.
The angle from the Fermi LAT boresight is 60.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250305645/quicklook/glg_skymap_all_bn250305645.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/bn250305645/quicklook/glg_healpix_all_bn250305645.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250305645/quicklook/glg_lc_medres34_bn250305645.gif