TITLE: GCN CIRCULAR NUMBER: 33376 SUBJECT: GRB 230227A: Fermi GBM Final Real-time Localization DATE: 23/02/27 10:32:34 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 10:22:03 UT on 27 Feb 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230227A (trigger 699186128.22906 / 230227432).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 348.0, Dec = -50.4 (J2000 degrees, equivalent to J2000 23h 11m, -50d 23'), with a statistical uncertainty of 1.8 degrees.

The angle from the Fermi LAT boresight is 120.0 degrees.

The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230227432/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/bn230227432/q...

The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230227432/q...