TITLE:   GCN CIRCULAR
NUMBER:  30090
SUBJECT: GRB 210528A: Fermi GBM Final Real-time Localization
DATE:    21/05/28 14:14:06 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 14:03:46 UT on 28 May 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210528A (trigger 643903431.162588 / 210528586).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 134.1, Dec = -16.3 (J2000 degrees, equivalent to J2000 08h 56m, -16d 18'), with a statistical uncertainty of 1.9 degrees.

The angle from the Fermi LAT boresight is 55.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210528586/quicklook/glg_skymap_all_bn210528586.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/bn210528586/quicklook/glg_healpix_all_bn210528586.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210528586/quicklook/glg_lc_medres34_bn210528586.gif