TITLE:   GCN CIRCULAR
NUMBER:  40136
SUBJECT: GRB 250411A: Fermi GBM Final Real-time Localization
DATE:    25/04/11 18:27:41 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 18:17:09 UT on 11 Apr 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250411A (trigger 766088234.189348 / 250411762).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 245.7, Dec = -13.9 (J2000 degrees, equivalent to J2000 16h 22m, -13d 54'), with a statistical uncertainty of 3.4 degrees.

The angle from the Fermi LAT boresight is 98.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250411762/quicklook/glg_skymap_all_bn250411762.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250411762/quicklook/glg_healpix_all_bn250411762.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250411762/quicklook/glg_lc_medres34_bn250411762.gif