TITLE:   GCN CIRCULAR
NUMBER:  31287
SUBJECT: GRB 211223B: Fermi GBM Final Real-time Localization
DATE:    21/12/23 08:33:43 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 08:23:22 UT on 23 Dec 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 211223B (trigger 661940607.257526 / 211223350).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 287.6, Dec = 42.2 (J2000 degrees, equivalent to J2000 19h 10m, 42d 12'), with a statistical uncertainty of 8.1 degrees.

The angle from the Fermi LAT boresight is 13.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn211223350/quicklook/glg_skymap_all_bn211223350.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn211223350/quicklook/glg_healpix_all_bn211223350.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn211223350/quicklook/glg_lc_medres34_bn211223350.gif