TITLE: GCN CIRCULAR NUMBER: 39435 SUBJECT: GRB 250223B: Fermi GBM Final Localization DATE: 25/02/23 18:43:58 GMT FROM: rhamburg@usra.edu
The Fermi GBM team reports the detection of a likely SHORT GRB
"At 10:19:23.76 UT on 23 February 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250223B (trigger 761998768/250223430). This trigger was initially classified as Unreliable Location by the flight software, but is in fact a GRB.
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 3.54, Dec = +43.49(J2000 degrees, equivalent to J2000 00h 14m, +43d 29'), with a statistical uncertainty of 13 degrees.
The angle from the Fermi LAT boresight is 56 degrees.
The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250223430/q...
The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250223430/q...
The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250223430/q..."
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