TITLE:   GCN CIRCULAR
NUMBER:  31812
SUBJECT: GRB 220401B: Fermi GBM Final Real-time Localization
DATE:    22/04/01 21:40:11 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 21:29:49 UT on 1 Apr 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220401B (trigger 670541394.48622 / 220401896).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 352.5, Dec = 42.9 (J2000 degrees, equivalent to J2000 23h 30m, 42d 53'), with a statistical uncertainty of 5.0 degrees.

The angle from the Fermi LAT boresight is 35.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220401896/quicklook/glg_skymap_all_bn220401896.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/bn220401896/quicklook/glg_healpix_all_bn220401896.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220401896/quicklook/glg_lc_medres34_bn220401896.gif