GCN Circular 8803
E. Bissaldi (MPE) and A. von Kienlin (MPE) report on behalf of the Fermi GBM Team: "At 07:57:23.11 UT on 12 January 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 090112 (trigger 253439845 / 090112332). The on-ground calculated location, using the GBM trigger data, is RA = 111.8, DEC = -30.3 (J2000 degrees, equivalent to 07h 27m, -30d 17'), with an uncertainty of 1.7 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 4 degrees. This burst was also independently detected by INTEGRAL SPI-ACS. The GRB lightcurve consists of two peaks with some substructure appearing at T0 and T0+4 s, respectively. A possible precursor is present around T0-20 s and additional weak emission is visible up to T0+50s. The event duration (T90) is about 65 s (8-1000 keV) and T50 is about 27 s (8-1000 keV). The time-averaged spectrum from T0-6 s to T0+18 s is best fit by a Band function with Epeak = 150 +/- 40 keV, alpha = -0.94 +/- 0.20 and beta = -2.01 +/- 0.19 (chi squared 464 for 456 d.o.f.). The event fluence (8-1000 keV) in this time interval is (5.2 +/- 1.0)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+4 s in the 8-1000 keV band is 7 +/- 2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."