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/quicklook/glg_skymap_all_bn250223430.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/bn250223430/quicklook/glg_healpix_all_bn250223430.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250223430/quicklook/glg_lc_medres34_bn250223430.gif"