TITLE: GCN CIRCULAR NUMBER: 9598 SUBJECT: GRB 090630: Fermi GBM detection DATE: 09/06/30 15:11:20 GMT FROM: Arne Rau at MPE Arne Rau (MPE) reports on behalf of the Fermi GBM Team: "At 07:27:21.17 UT on 30 June 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 090630 (trigger 268039643 / 090630311). The on-ground calculated location, using the GBM trigger data, is RA = 146.6, DEC = -46.6 (J2000 degrees, equivalent to 09 h 24 m, -46 d 36 '), with an uncertainty of 5.8 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 75 degrees. This burst was also detected (although not triggered) by INTEGRAL SPI-ACS. The GBM light curve consists of a single peak with a duration (T90) of about 5.1 s (8-1000 keV). The time-averaged spectrum from T0-1.024 s to T0+4.096 s is best fit by a power law function with an exponential high energy cutoff. The power law index is -1.5 +/- 0.1 and the cutoff energy, parameterized as Epeak, is 79 +/- 13 keV (chi squared 537 for 475 d.o.f.). The event fluence (8-1000 keV) in this time interval is (5.1 +/- 0.7)E-07 erg/cm^2. The 2.048-sec peak photon flux measured starting from T0+0.003 s in the 8-1000 keV band is 2.78 +/- 0.05 ph/s/cm^2. A Band function fits the spectrum equally well (chi squared 535 for 474 d.o.f.) with Epeak= 71 +/- 24 keV, alpha = -1.5 +/- 0.2 and beta = -2.3 +/- 0.4. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."