TITLE: GCN CIRCULAR NUMBER: 12801 SUBJECT: GRB 120102A: Fermi GBM observation DATE: 12/01/03 16:58:55 GMT FROM: Shaolin Xiong at UAH S. Xiong (UAH) reports on behalf of the Fermi GBM Team: "At 02:16:23.24 UT on 02 Jan 2012, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 120102A (trigger 347163385 / 120102095), which was also detected by the Swift BAT/XRT/UVOT (F. E. Marshall et al. 2012, GCN 12794) The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 84 degrees. The GBM light curve consists of two main pulses with a duration (T90) of about 17 s (50-300 keV). The time-averaged spectrum from T0-1 s to T0+13 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.19 +/- 0.03 and the cutoff energy, parameterized as Epeak, is 380 +/- 33 keV. A Band function fits the spectrum equally well with Epeak = 291 +/- 33 keV, alpha = -1.13 +/- 0.04, and beta = -2.14 +/- 0.13. The event fluence (10-1000 keV) in this time interval is (1.26 +/- 0.03)E-5 erg/cm^2. The 64 ms peak photon flux measured starting from T0+4.8 s in the 10-1000 keV band is 22.8 +/- 1.6 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."