TITLE:   GCN CIRCULAR
NUMBER:  30059
SUBJECT: GRB 210520A: Fermi GBM Final Real-time Localization
DATE:    21/05/20 19:17:25 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 19:07:02 UT on 20 May 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210520A (trigger 643230427.939988 / 210520797).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 147.9, Dec = -67.0 (J2000 degrees, equivalent to J2000 09h 51m, -67d 00'), with a statistical uncertainty of 3.7 degrees.

The angle from the Fermi LAT boresight is 15.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210520797/quicklook/glg_skymap_all_bn210520797.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/bn210520797/quicklook/glg_healpix_all_bn210520797.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210520797/quicklook/glg_lc_medres34_bn210520797.gif