TITLE:   GCN CIRCULAR
NUMBER:  31811
SUBJECT: GRB 220401A: Fermi GBM Final Localization
DATE:    22/04/01 17:40:40 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

The Fermi GBM team reports the detection of a likely LONG GRB.

At 10:17:40.89 UT on 1 April 2022, the Fermi Gamma-ray Burst Monitor
(GBM) triggered and located GRB 220401A (trigger  670501065/
220401429). The trigger was initially classified as a Solar flare but
it is in fact a GRB.

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 8.0, Dec = 50.0 (J2000 degrees, equivalent to J2000 0h 3m, 50d
00'), with a statistical uncertainty of 4.2 degrees.

The angle from the Fermi LAT boresight is 82.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220401429/quicklook/glg_skymap_all_bn220401429.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/bn220401429/quicklook/glg_healpix_all_bn220401429.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220401429/quicklook/glg_lc_medres34_bn220401429.gif