TITLE:   GCN CIRCULAR
NUMBER:  33129
SUBJECT: GRB 221231A: Fermi GBM Final Real-time Localization
DATE:    22/12/31 21:57:19 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 21:46:05 UT on 31 Dec 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 221231A (trigger 694215970.129412 / 221231907).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 332.7, Dec = 36.5 (J2000 degrees, equivalent to J2000 22h 10m, 36d 30'), with a statistical uncertainty of 5.2 degrees.

The angle from the Fermi LAT boresight is 50.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221231907/quicklook/glg_skymap_all_bn221231907.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221231907/quicklook/glg_healpix_all_bn221231907.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221231907/quicklook/glg_lc_medres34_bn221231907.gif