TITLE:   GCN CIRCULAR
NUMBER:  29837
SUBJECT: GRB 210420A: Fermi GBM Final Real-time Localization
DATE:    21/04/20 05:19:45 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 05:09:29 UT on 20 Apr 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210420A (trigger 640588174.204176 / 210420215).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 253.4, Dec = 12.2 (J2000 degrees, equivalent to J2000 16h 53m, 12d 11'), with a statistical uncertainty of 21.8 degrees.

The angle from the Fermi LAT boresight is 80.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210420215/quicklook/glg_skymap_all_bn210420215.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/bn210420215/quicklook/glg_healpix_all_bn210420215.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210420215/quicklook/glg_lc_medres34_bn210420215.gif