TITLE: GCN CIRCULAR NUMBER: 14154 SUBJECT: GRB 130127A: Fermi GBM detection DATE: 13/01/28 18:54:47 GMT FROM: Veronique Pelassa at UAH V. Pelassa (UAH) reports on behalf of the Fermi GBM Team: "At 17:50:23.93 UT on 27 January 2013, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 130127A (trigger 381001826 / 130127743). The on-ground calculated location, using the GBM trigger data, is RA = 251.1, DEC = -17.1 (J2000 degrees, equivalent to 16 h 44 m, -17 d 04'), with an uncertainty of 8.5 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 27 degrees. The GBM light curve shows a bright short peak and a fainter tail, with a duration (T90) of about 0.45 s (50-300 keV). The time-averaged spectrum from T0-0.064 s to T0+0.064 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.03 +/- 0.29 and the cutoff energy, parameterized as Epeak, is 770 +/- 190 keV (Castor statistics 751 for 725 d.o.f.). The event fluence (10-1000 keV) in this time interval is (4.9 +/- 0.4)E-07 erg/cm^2. The 64-msec peak photon flux measured starting from T0-0.064 s in the 10-1000 keV band is 7.4 +/- 0.9 ph/s/cm^2. A Band function fits the spectrum equally well (Castor statistics 750.29 for 724 d.o.f.) with Epeak= 700 +/- 210 keV, alpha = 0.03 +/- 0.34 and beta = -2.4 +/- 0.7. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."