TITLE: GCN CIRCULAR NUMBER: 40418 SUBJECT: GRB 250510B: Fermi GBM Final Localization DATE: 25/05/10 09:49:01 GMT FROM: A. Holzmann Airasca at University of Trento and INFN Bari a.holzmannairasca@unitn.it

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

"At 06:41:54.06 UT on 10 May 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250510B (trigger 768552119/250510279).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 128.93, Dec = -24.76 (J2000 degrees, equivalent to J2000 08h 35m, -24d 45'), with a statistical uncertainty of 2.39 degrees.

The angle from the Fermi LAT boresight is 103 degrees.

The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250510279/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/bn250510279/q...

The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250510279/q..."

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