GCN Circular 9301
M. S. Briggs (UAH) reports on behalf of the Fermi GBM Team: "At 15:27:00.86 UT on 27 April 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 090427B (trigger 262538822 / 090427644). The on-ground calculated location, using the GBM trigger data, is RA = 210.0, DEC = -45.7 (J2000 degrees, equivalent to 14 h 00 m, -45 d 42'), with an uncertainty of 11.8 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 14 degrees. The GBM light curve consists of a single peak with a duration about 7 s (8-1000 keV). The time-averaged spectrum from T0-4.096 s to T0+2.048 s is well fit by a simple power law function with index -1.1 +/- 0.1. The event fluence (8-1000 keV) in this time interval is (8.0 +/- 0.5)E-7 erg/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."