TITLE: GCN CIRCULAR NUMBER: 16321 SUBJECT: GRB 140523A: Fermi GBM detection DATE: 14/05/23 15:02:50 GMT FROM: Andreas von Kienlin at MPE A. von Kienlin(MPE) and V. Connaughton (UAH) report on behalf of the Fermi GBM Team: "At 03:05:57.62 UT on 23 May 2014, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 140523A (trigger 422507160 / 140523129). The on-ground calculated location, using the GBM trigger data, is RA = 128.7, DEC = 26.9 (J2000 degrees, equivalent to 08 h 35 m, 26 d 54 '), with an uncertainty of 1.0 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which is currently estimated to be 2 to 3 degrees). The angle from the Fermi LAT boresight is 60 degrees. The GBM light curve consists of multiple peaks with a duration (T90) of about 20 s (50-300 keV). The time-averaged spectrum from T0+0.003 s to T0+22.720 s is well fit by a Band function with Epeak = 270.7 (+8.1/-8.6) keV, alpha = -1.05 +/- 0.01 , and beta = -2.73 (+0.14/-0.19). The event fluence (10-1000 keV) in this time interval is (5.13 +/- 0.04)E-05 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0+7.232 s in the 10-1000 keV band is 37.7 +/- 0.5 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."