GCN Circular 40104
Subject
GRB 250407A: Fermi GBM Final Real-time Localization
Date
2025-04-07T15:58:59Z (8 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 15:48:21 UT on 7 Apr 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250407A (trigger 765733706.065626 / 250407659).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 110.3, Dec = 42.0 (J2000 degrees, equivalent to J2000 07h 21m, 42d 00'), with a statistical uncertainty of 1.0 degrees.
The angle from the Fermi LAT boresight is 118.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250407659/quicklook/glg_skymap_all_bn250407659.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/bn250407659/quicklook/glg_healpix_all_bn250407659.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250407659/quicklook/glg_lc_medres34_bn250407659.gif