TITLE: GCN CIRCULAR NUMBER: 32147 SUBJECT: GRB 220528A: Fermi GBM Final Localization DATE: 22/05/28 15:21:54 GMT FROM: Joe Mangan at UCD The Fermi GBM team reports the detection of a likely short GRB. At 06:12:47.41 UT on 28 May 2022, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 220528A (trigger 675411172 / 220528259). The on-ground calculated location, using the GBM trigger data, is RA = 311.2, DEC = 24.3 (J2000 degrees, equivalent to 20 h 44 m, 24 d 18 '), with a statistical uncertainty of 4.9 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which we have characterized as a core-plus-tail model, with 90% of GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ). The angle from the Fermi LAT boresight at the GBM trigger time is 68 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220528259/quicklook/glg_skymap_all_bn220528259.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/bn220528259/quicklook/glg_healpix_all_bn220528259.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220528259/quicklook/glg_lc_medres34_bn220528259.gif