GCN Circular 9119
E. Bissaldi (MPE) reports on behalf of the Fermi GBM Team: "At 06:54:01.44 UT on 09 April 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 090409 (trigger 260952843 / 090409288). The on-ground calculated location, using the GBM trigger data, is RA = 302.1, DEC = +1.1 (J2000 degrees, equivalent to 20h 08m, 01d 06'), with an uncertainty of 7.9 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 90 degrees. This weak and long GRB consists of a single peak with a duration (T90) of about 20 s (8-1000 keV). The time-averaged spectrum from T0 to T0+5.1 s is adequately fit by a power law function with an exponential high energy cutoff. The power law index is 1.2 +/- 0.7 and the cutoff energy, parameterized as Epeak, is 137 +/- 17 keV (chi squared 346 for 356 d.o.f.). The event fluence (8-1000 keV) in this time interval is (6.14 +/- 0.26)E-07 erg/cm^2. The 1-sec peak photon flux measured starting from T0+4 s in the 8-1000 keV band is 1.36 +/- 0.14 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."