GCN Circular 9228
Sheila McBreen (UCD/MPE) reports on behalf of the Fermi GBM Team: "At 03:35:17.07 UT on 22 April 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 090422 (trigger 262064119 / 090422150) which was also detected by the Swift-BAT (Ukwatta et al. 2009, GCN 9185 & Markwardt et al. 2009, GCN 9195). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 29 degrees. The GBM light curve consists of 2 pulses with a duration (T90) of about 10 s (8-1000 keV). The time-averaged spectrum from T0-2.4 s to T0+10.8 s is adequately fit by a simple power law function with index 1.81 +/- 0.15 (chi squared 358 for 361 d.o.f.). The event fluence (8-1000 keV) in this time interval is (1.0 +/- 0.1)E-6 erg/cm^2. The 0.128 sec peak photon flux measured starting from T0-0.256 s in the 8-1000 keV band is 7.8 +/- 0.5 ph/s/cm^2.