TITLE: GCN CIRCULAR NUMBER: 20452 SUBJECT: GRB 170113A: Fermi GBM observations DATE: 17/01/13 18:39:20 GMT FROM: Peter Veres at UAH P. Veres (UAH), C. Meegan (UAH) and A. von Kienlin (MPE) report on behalf of the Fermi GBM Team: "At 10:04:10.11 UT on 13 January 2017, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 170113A (trigger 505994655 / 170113420). which was also detected by the Swift/BAT (Evans et al., GCN 20446). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is 145 degrees. The GBM light curve shows a single pulse with a duration (T90) of about 49 s (50-300 keV). The time-averaged spectrum from T0-10 s to T0+47 s is adequately fit by a simple power law function with index -2.05 +/- 0.08. The event fluence (10-1000 keV) in this time interval is (3.8 +/- 0.4)E-6 erg/cm^2. The 1-sec peak photon flux measured starting from T0+4.5 s in the 10-1000 keV band is 2.9 +/- 0.4 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."