TITLE: GCN CIRCULAR NUMBER: 9059 SUBJECT: GRB 090326: Fermi GBM detection DATE: 09/03/31 04:24:09 GMT FROM: Michael S. Briggs at UAH and MSFC Michael S. Briggs (UAH) reports on behalf of the Fermi GBM Team: "At 15:10:49.48 UT on 26 March 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 090326 (trigger 259773051 / 090326633). The on-ground calculated location, using the GBM trigger data, is RA = 259.6, DEC = -11.6 (J2000 degrees, equivalent to 17 h 18 m, -11 d 36'), with an uncertainty of 1.8 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 103 degrees. The GBM light curve shows two peaks with a duration (T90) of about 11.2 s (8-1000 keV). The time-averaged spectrum from T0-3.072 s to T0+10.240 s is well fit by a power law function with an exponential high energy cutoff. The power law index is -0.86 +/- 0.22 and the cutoff energy, parameterized as Epeak, is 75. +/- 8. keV. The fluence in this time interval is (8.6 +/- 1.8)E-07 erg/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."