GCN Circular 10146
J. Michael Burgess (UAH) and Sylvain Guiriec (UAH) report on behalf of the Fermi GBM Team: "At 19:52:26.86 UT on 30 October 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 091030 (trigger 278625148 / 091030828). The on-ground calculated location, using the GBM trigger data, is RA = 41.67, DEC = 21.54 (J2000 degrees, equivalent to 17h 40m 12, 21d 32'), with an uncertainty of 1.2 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 100 degrees. The GBM light curve consists of 2 bright peaks followed by 2 dimmer peaks. with a duration (T90) of about 160 s (8-1000 keV). The time-averaged spectrum from T0-1.7 s to T0+40 s is best fit by a Band function with Epeak = 507 +/- 30 keV, alpha = -0.88 +/- 0.02, and beta = -2.2 +/- 0.1 (castor C-stat 626 for 478 d.o.f.). The event fluence (8-1000 keV) in this time interval is (3.03 +/- 0.043) E-5 erg/cm^2. The 1-sec peak photon flux measured starting from T0+17.54 s in the 8-1000 keV band is 9.58 +/- 0.23 ph/s/cm^2. The spectral and temporal analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."