TITLE: GCN CIRCULAR NUMBER: 9412 SUBJECT: GRB 090519B: Fermi GBM detection DATE: 09/05/20 15:32:50 GMT FROM: Andreas von Kienlin at MPE A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team: "At 11:05:27.54 UT on 19 May 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 090519B (trigger 264423929 / 090519462). The on-ground calculated location, using the GBM trigger data, is RA = 105.9, DEC = -56.7 (J2000 degrees, equivalent to 07h 04m, 56d 42'), with an uncertainty of 3.9 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 18 degrees. The GBM light curve shows a single peak lasting about 4 seconds superimposed on a lower-level continuum. The burst duration (T90) is about 87 s (8-1000 keV). The time-averaged spectrum from T0-2.432 s to T0+1.152 s is well fit by a simple power law function with index -1.63 +/- 0.05 (chi squared 822 for 720 d.o.f.). The event fluence (8-1000 keV) in this time interval is (1.40 +/- 0.01)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0-0.640 s in the 8-1000 keV band is 5.02 +/- 0.14 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."