TITLE:   GCN CIRCULAR
NUMBER:  34734
SUBJECT: GRB 230918B: Fermi GBM Final Real-time Localization
DATE:    23/09/19 00:05:51 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 23:55:14 UT on 18 Sep 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230918B (trigger 716774119.92359 / 230918997).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 307.7, Dec = -48.4 (J2000 degrees, equivalent to J2000 20h 30m, -48d 23'), with a statistical uncertainty of 6.3 degrees.

The angle from the Fermi LAT boresight is 47.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230918997/quicklook/glg_skymap_all_bn230918997.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/bn230918997/quicklook/glg_healpix_all_bn230918997.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230918997/quicklook/glg_lc_medres34_bn230918997.gif