TITLE:   GCN CIRCULAR
NUMBER:  41128
SUBJECT: GRB 250721A: Fermi GBM Final Localization
DATE:    25/07/21 11:11:33 GMT
FROM:    A. Holzmann Airasca at University of Trento and INFN Bari <a.holzmannairasca@unitn.it>

The Fermi GBM team reports the detection of a likely LONG GRB

"At 09:37:46.53 UT on 21 July 2025, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 250721A (trigger 774783471/250721401).

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 76.94, Dec = -12.37 (J2000 degrees, equivalent to J2000 5h 7m, -12d 22'),
with a statistical uncertainty of 10.20 degrees.

The angle from the Fermi LAT boresight is 82 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250721401/quicklook/glg_skymap_all_bn250721401.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/bn250721401/quicklook/glg_healpix_all_bn250721401.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250721401/quicklook/glg_lc_medres34_bn250721401.gif"