TITLE:   GCN CIRCULAR
NUMBER:  34754
SUBJECT: GRB 230921A: Fermi GBM Final Real-time Localization
DATE:    23/09/21 02:51:55 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

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

At 02:41:32 UT on 21 Sep 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230921A (trigger 716956897.615146 / 230921112).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 239.4, Dec = -33.4 (J2000 degrees, equivalent to J2000 15h 57m, -33d 23'), with a statistical uncertainty of 6.9 degrees.

The angle from the Fermi LAT boresight is 39.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230921112/quicklook/glg_skymap_all_bn230921112.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230921112/quicklook/glg_healpix_all_bn230921112.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230921112/quicklook/glg_lc_medres34_bn230921112.gif