TITLE:   GCN CIRCULAR
NUMBER:  32861
SUBJECT: GRB 221027A: Fermi GBM Final Real-time Localization
DATE:    22/10/27 04:21:08 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 04:09:34 UT on 27 Oct 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 221027A (trigger 688536579.352978 / 221027173).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 189.4, Dec = -10.0 (J2000 degrees, equivalent to J2000 12h 37m, -10d 00'), with a statistical uncertainty of 1.9 degrees.

The angle from the Fermi LAT boresight is 52.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221027173/quicklook/glg_skymap_all_bn221027173.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/bn221027173/quicklook/glg_healpix_all_bn221027173.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221027173/quicklook/glg_lc_medres34_bn221027173.gif