TITLE: GCN CIRCULAR NUMBER: 34822 SUBJECT: GRB231017A: Fermi GBM Final Localization DATE: 23/10/17 14:51:29 GMT FROM: Joe Mangan at IJCLab <joseph.mangan@ijclab.in2p3.fr> The Fermi GBM team reports the detection of a likely Long GRB. At 08:05:03.30 UT on 17 October 2023, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB231017A (trigger 719222708 / 231017337). The on-ground calculated location, using the GBM trigger data, is RA = 88.8, DEC = 57.2 (J2000 degrees, equivalent to 5h 55m, 57d 09'), with a statistical uncertainty of 5.7 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which we have characterized as a core-plus-tail model, with 90% of GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ). The angle from the Fermi LAT boresight at the GBM trigger time is 58 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn231017337/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/bn231017337/q... The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn231017337/q... View this GCN Circular online at https://gcn.nasa.gov/circulars/34822. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...