TITLE: GCN CIRCULAR NUMBER: 15688 SUBJECT: GRB 140105A: Fermi GBM detection DATE: 14/01/05 21:39:05 GMT FROM: Shaolin Xiong at UAH Shaolin Xiong (UAH) and Valerie Connaughton (UAH) report on behalf of the Fermi GBM Team: "At 01:33:01.01 UT on 05 January 2014, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 140105A (trigger 410578384 / 140105065). The on-ground calculated location, using the GBM trigger data, is RA = 208.22, DEC = 50.17 (J2000 degrees, equivalent to 13 h 53 m, 50 d 10 '), with an uncertainty of 6 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 72 degrees. The optical afterglow candidates reported by iPTF (Singer et al. GCN 15686) lie within the 1-sigma (statistical and systematic) uncertainty region surrounding the GBM localization. The GBM light curve consists of weak pulses with a duration (T90) of about 0.8 s (50-300 keV). The time-averaged spectrum from T0-0.064 s to T0+0.64 s is well fit by a power law function with an exponential high-energy cutoff. The power law index is -0.98 +/- 0.11 and the cutoff energy, parameterized as Epeak, is 1200 +/- 500 keV. The event fluence (10-1000 keV) in this time interval is (8.7 +/- 0.6)E-7 erg/cm^2. The 64 ms peak photon flux measured starting from T0 in the 10-1000 keV band is 8.2 +/- 1.2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."