TITLE: GCN CIRCULAR NUMBER: 14940 SUBJECT: GRB 130623A: Fermi GBM detection DATE: 13/06/27 17:07:07 GMT FROM: David Byrne at UCD D. Byrne (UCD), A. von Kienlin (MPE) and W. Paciesas (UAH) report on the behalf of the Fermi GBM Team: "At 11:42:47.05 UT on 23 June 2013, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 130623A (trigger 393680570 / 130623488), which was also detected by the Swift/BAT (J. R. Cummings 2013, GCN 14921). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 46 degrees. The GBM light curve consists of four peaks within 30s of the trigger time with a duration (T90) of about 21 s (50-300 keV). The time-averaged spectrum from T0-6.144s to T0+24.576s is well fit by a power law function with an exponential high-energy cutoff. The power law index is -1.03 +/- 0.53 and the cutoff energy, parameterized as Epeak, is 26.11 +/- 4.67 keV. The event fluence (10-1000 keV) in this time interval is (2.63 +/- 0.20)E-06 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0+13.568 s in the 10-1000 keV band is 5.07 +/- 0.25 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog." -- David Byrne BSc. School of Physics, Science Center North, University College Dublin, Belfield, Dublin 4, Ireland.