TITLE: GCN CIRCULAR NUMBER: 14261 SUBJECT: GRB 130305A: Fermi GBM observation DATE: 13/03/06 00:34:45 GMT FROM: Shaolin Xiong at UAH Hoi-Fung Yu (MPE) and Shaolin Xiong (UAH) report on behalf of the Fermi GBM Team: "At 11:39:11.37 UT on 05 March 2013, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 130305A (trigger 384176354 / 130305486), which was also detected by the Fermi/LAT (S. Guiriec et al., GCN 14260) and the Swift/BAT (Cummings et al., GCN 14257). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is about 44 degrees. This burst was also independently detected by INTEGRAL SPI-ACS. The GBM light curve shows single pulse with a tail with a duration (T90) of about 29 s (50-300 keV). The time-averaged spectrum from T0-0 s to T0+30 s is best fit by a Band function with Epeak = 640 +/- 23 keV, alpha = -0.67 +/- 0.02, and beta = -2.4 +/- 0.1. The event fluence (10-1000 keV) in this time interval is (5.7 +/- 0.07)E-5 erg/cm^2. The 1-sec peak photon flux measured starting from T0+5.2 s in the 10-1000 keV band is 25.4 +/- 0.3 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."