TITLE:   GCN CIRCULAR
NUMBER:  33310
SUBJECT: GRB 230209B: Fermi GBM Final Real-time Localization
DATE:    23/02/09 22:43:06 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 22:32:36 UT on 9 Feb 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230209B (trigger 697674761.889546 / 230209939).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 87.2, Dec = 23.5 (J2000 degrees, equivalent to J2000 05h 48m, 23d 30'), with a statistical uncertainty of 1.8 degrees.

The angle from the Fermi LAT boresight is 82.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230209939/quicklook/glg_skymap_all_bn230209939.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/bn230209939/quicklook/glg_healpix_all_bn230209939.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230209939/quicklook/glg_lc_medres34_bn230209939.gif