GCN Circular 9390
Colleen A. Wilson-Hodge (NASA/MSFC) reports on behalf of the Fermi GBM Team: "At 21:58:47.92 UT on 13 May 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 090513 (trigger 263944729 / 090513.916). The on-ground calculated location, using the GBM trigger data, is RA = 269.8, DEC = -31.6 (J2000 degrees, equivalent to 17 h 59 m, -31 d 36'), with an uncertainty of 4.6 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 89 degrees. The GBM light curve shows a broad peak with a duration (T90) of about 23 s (8-1000 keV). The time-averaged spectrum from T0-1 s to T0+19 s is adequately fit by a power law function with an exponential high energy cutoff. The power law index is -0.9 +/- 0.1 and the cutoff energy, parameterized as Epeak, is 850 +/- 390 keV The event fluence (8-1000 keV) in this time interval is (6.8 +/- 0.4)E-06 erg/cm^2. The 1 s peak photon flux measured starting from T0+5.1 s in the 8-1000 keV band is 2.7 +/- 0.2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."