TITLE: GCN CIRCULAR NUMBER: 8678 SUBJECT: GRB 081215A: Fermi GBM detection DATE: 08/12/17 22:42:55 GMT FROM: Rob Preece at UAH Robert Preece (UAH) reports on behalf of the Fermi GBM Team: "At 18:48:36.85 UT on 15 December 2008, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 081215 (trigger 251059717 / 081215784). The on-ground calculated location, using the GBM trigger data, is RA = 135.0, DEC = +53.8 (J2000 degrees, equivalent to 09 h 00 m 00.00, 53 d 48 '), with an uncertainty of 1.0 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 86 degrees. The on-board GBM Flight Software localization for this very bright burst, as reported in the GCN Notices, was consistent with a position on the Earth's surface, likely due to a large scattered flux from the Earth. This resulted in an autonomous and erroneous "100% Below horizon" classification for this event which prevented an automated ground localization from being sent through the GCN notice system. The GBM light curve consists of a very hard narrow pulse on top of a broader emission episode, with a duration (T90) of about 7.7 s (8-1000 keV). The time-averaged spectrum from T0-1.79 s to T0+13.57 s is best fit by a Band function with Epeak = 304 +/- 11 keV, alpha = -0.585 +/- 0.022, and beta = -2.066 +/- 0.038. The event fluence (8-1000 keV) in this time interval is (3.54 +/- 0.05)E-6 erg/cm^2. The 1-sec photon flux measured starting from T0+1.28 s in the 8-1000 keV band is 68.9 +/- 1.0 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."