TITLE:   GCN CIRCULAR
NUMBER:  34856
SUBJECT: GRB 231020A: Fermi GBM Final Real-time Localization
DATE:    23/10/20 19:04:32 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 18:56:58 UT on 20 Oct 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 231020A (trigger 719521023.300322 / 231020790).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 317.5, Dec = -28.7 (J2000 degrees, equivalent to J2000 21h 10m, -28d 41'), with a statistical uncertainty of 1.0 degrees.

The angle from the Fermi LAT boresight is 87.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn231020790/quicklook/glg_skymap_all_bn231020790.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/bn231020790/quicklook/glg_healpix_all_bn231020790.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn231020790/quicklook/glg_lc_medres34_bn231020790.gif