TITLE:   GCN CIRCULAR
NUMBER:  35998
SUBJECT: GRB 240331A: Fermi GBM Final Real-time Localization
DATE:    24/04/01 00:05:53 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 23:55:19 UT on 31 Mar 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240331A (trigger 733622124.6772 / 240331997).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 31.4, Dec = 0.9 (J2000 degrees, equivalent to J2000 02h 05m, 0d 54'), with a statistical uncertainty of 5.8 degrees.

The angle from the Fermi LAT boresight is 62.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240331997/quicklook/glg_skymap_all_bn240331997.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240331997/quicklook/glg_healpix_all_bn240331997.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240331997/quicklook/glg_lc_medres34_bn240331997.gif