TITLE: GCN CIRCULAR NUMBER: 17282 SUBJECT: GRB 150105A: Fermi GBM detection DATE: 15/01/05 15:57:11 GMT FROM: Oliver Roberts at UCD/Fermi O.J. Roberts (UCD) reports on behalf of the Fermi GBM Team: "At 06:10:00.46 UT on the 5th of January 2014, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 150105A (trigger 442131003 / 150105257). The GBM on-ground location, using the Fermi GBM trigger data, is RA = 124.3, Dec =-14.8, with an uncertainty of 1.0 degree (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 about 86 degrees. The GBM light curve consists of several bright peaks with a duration (T90) of about 74 s (50-300 keV). The time- averaged spectrum from T0+3.0 s to T0+76.7 s is well fit by a Band function with Epeak = 52 +/- 2 keV, Alpha = -0.91 +/- 0.07 and Beta = -2.25 +/- 0.03. The event fluence (10-1000 keV) in this time interval is (4.4 +/- 0.1)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+44.6 s in the 10-1000 keV band is 23.5 +/- 0.4 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."