TITLE: GCN CIRCULAR NUMBER: 14271 SUBJECT: GRB 130307A: Fermi GBM detection DATE: 13/03/08 05:19:20 GMT FROM: Veronique Pelassa at UAH V. Pelassa (UAH) reports on behalf of the Fermi GBM Team: "At 03:01:44.47 UT on March 7 2013, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 130307A (trigger 384318107 / 130307126). The on-ground calculated location, using the GBM trigger data, is RA = 153.7, DEC = 18.3 (J2000 degrees, equivalent to +10h 12m, +18d 16'), with an uncertainty of 3.3 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 67 degrees. This burst was also independently detected by INTEGRAL SPI-ACS. An IPN triangulation will be issued in a forthcoming circular. The GBM light curve consists of a single pulse with a duration (T90) of about 0.4 s (50-300 keV). The time-averaged spectrum from T0-0.64 s to T0+0.032 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.78 +/- 0.06 and the cutoff energy, parameterized as Epeak, is 1670 +/- 350 keV (Castor statistics 816 for 728 d.o.f.). The event fluence (10-1000 keV) in this time interval is (1.43 +/- 0.05)E-06 erg/cm^2. The 64-msec peak photon flux measured starting from T0+0.064 s in the 10-1000 keV band is 9.9 +/- 1.1 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."