TITLE:   GCN CIRCULAR
NUMBER:  31025
SUBJECT: GRB 211031A: Fermi GBM Final Real-time Localization
DATE:    21/10/31 04:21:52 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 SHORT GRB

At 04:11:39 UT on 31 Oct 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 211031A (trigger 657346304.154694 / 211031175).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 72.0, Dec = -54.3 (J2000 degrees, equivalent to J2000 04h 47m, -54d 17'), with a statistical uncertainty of 10.7 degrees.

The angle from the Fermi LAT boresight is 28.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn211031175/quicklook/glg_skymap_all_bn211031175.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/bn211031175/quicklook/glg_healpix_all_bn211031175.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn211031175/quicklook/glg_lc_medres34_bn211031175.gif