GCN Circular 9486
Elisabetta Bissaldi (MPE) reports on behalf of the Fermi GBM Team: "At 13:32:22.85 UT on 02 June 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 090602 (trigger 265642344 / 090602564). The on-ground calculated location, using the GBM trigger data, is RA = 248.9, DEC = -65.0 (J2000 degrees, equivalent to 16h 36m, -65d 00'), with an uncertainty of 3.4 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 112 degrees. This burst was also independently detected by INTEGRAL SPI-ACS. The GBM light curve consists of a broad single peak with a duration (T90) of about 16 s (8-1000 keV). The time-averaged spectrum from T0-1.3s to T0+9s is best fit by a power law function with an exponential high energy cutoff. The power law index is -0.56 +/- 0.14 and the cutoff energy, parameterized as Epeak, is 503 +/- 91 keV (chi squared 327 for 358 d.o.f.). The event fluence (8-1000 keV) in this time interval is (5.7 +/- 0.3)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+2.8 s in the 8-1000 keV band is 3.62 +/- 0.17 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."