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TITLE:   GCN CIRCULAR
NUMBER:  30758
SUBJECT: GRB 210903C: Fermi GBM Final Real-time Localization
DATE:    21/09/03 17:37:06 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 17:26:58 UT on 3 Sep 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210903C (trigger 652382823.653196 / 210903727).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 155.0, Dec = 22.0 (J2000 degrees, equivalent to J2000 10h 20m, 22d 00'), with a statistical uncertainty of 4.2 degrees.

The angle from the Fermi LAT boresight is 72.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210903727/quicklook/glg_skymap_all_bn210903727.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/bn210903727/quicklook/glg_healpix_all_bn210903727.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210903727/quicklook/glg_lc_medres34_bn210903727.gif