TITLE: GCN CIRCULAR NUMBER: 39120 SUBJECT: GRB 250202B: Fermi GBM Final Real-time Localization DATE: 25/02/02 04:07:47 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 03:57:17 UT on 2 Feb 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250202B (trigger 760161442.322744 / 250202165).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 347.8, Dec = 16.5 (J2000 degrees, equivalent to J2000 23h 11m, 16d 30'), with a statistical uncertainty of 1.4 degrees.

The angle from the Fermi LAT boresight is 128.0 degrees.

The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250202165/q...

The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250202165/q...

The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250202165/q...

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