TITLE: GCN CIRCULAR NUMBER: 33385 SUBJECT: GRB 230301A: Fermi GBM Final Real-time Localization DATE: 23/03/01 06:50:48 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 06:40:10 UT on 1 Mar 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230301A (trigger 699345615.891978 / 230301278).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 319.1, Dec = 68.3 (J2000 degrees, equivalent to J2000 21h 16m, 68d 17'), with a statistical uncertainty of 3.0 degrees.

The angle from the Fermi LAT boresight is 15.0 degrees.

The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230301278/q...

The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230301278/q...

The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230301278/q...