TITLE:   GCN CIRCULAR
NUMBER:  35511
SUBJECT: GRB 240109B: Fermi GBM Final Real-time Localization
DATE:    24/01/09 21:41:29 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 21:30:52 UT on 9 Jan 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240109B (trigger 726528657.301666 / 240109896).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 241.5, Dec = -44.3 (J2000 degrees, equivalent to J2000 16h 06m, -44d 17'), with a statistical uncertainty of 12.2 degrees.

The angle from the Fermi LAT boresight is 91.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240109896/quicklook/glg_skymap_all_bn240109896.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/bn240109896/quicklook/glg_healpix_all_bn240109896.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240109896/quicklook/glg_lc_medres34_bn240109896.gif