TITLE: GCN CIRCULAR NUMBER: 31658 SUBJECT: GRB 220228A: Fermi GBM Final Localization DATE: 22/02/28 21:52:12 GMT FROM: Joshua Wood at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 10:30:05.92 UT on 28 Feb 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220228A (trigger 667737010 / 220228438). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 321.0, Dec = -16.9 (J2000 degrees, equivalent to J2000 21h 24m, -16d 54'), with a statistical uncertainty of 8.5 degrees. The angle from the Fermi LAT boresight is 28.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220228438/quicklook/glg_skymap_all_bn220228438.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220228438/quicklook/glg_healpix_all_bn220228438.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220228438/quicklook/glg_lc_medres34_bn220228438.gif