GCN Circular 9055
A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team: "At 06:42:22.10 UT on 30 March 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 090330 (trigger 260088144 / 090330279). The on-ground calculated location, using the GBM trigger data, is RA = 159.2, DEC = -7.7 (J2000 degrees, equivalent to 10h 37m, -07d 42'), with an uncertainty of 2.1 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 50 degrees. The GBM light curve consists of a slowly rising pulse with a duration (T90) of about 80 s (8-1000 keV). The time-averaged spectrum from T0-2.048 s to T0+24.576 s is well fit by a power law function with an exponential high energy cutoff. The power law index is -1.01 +/- 0.04 and the cutoff energy, parameterized as Epeak, is 261 +/- 18 keV (chi squared 606 for 609 d.o.f.). The event fluence (8-1000 keV) in this time interval is (1.14 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+12.288 s in the 8-1000 keV band is 6.8 +/- 0.3 ph/s/cm^2. A Band function fits the spectrum equally well (chi squared 605 for 608 d.o.f.) with Epeak= 246 +/- 25 keV, alpha = -0.99 +/- 0.05 and beta = -2.68 +/- 0.55. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."