TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5462 SUBJECT: GRB 060813: A long, bright GRB detected with Suzaku WAM DATE: 06/08/16 20:18:47 GMT FROM: Masanori Ohno at Hiroshima U K.Yamaoka, S.Sugita (Aoyama Gakuin U.), M.Ohno, T.Takahashi, T.Asano, T.Uehara, Y.Fukazawa (Hiroshima U.), Y.Terada, T.Tamagawa, M.Suzuki (RIKEN), K.Abe, K.Onda, M.Suzuki, M.Tashiro (Saitama U.), S.Hong (Nihon U.) K.Nakazawa, T.Takahashi (ISAS/JAXA), T.Enoto, R.Miyawaki, K.Kokubun (Univ. of Tokyo) on behalf of the Suzaku HXD-II team report: The bright, long burst, GRB 060813 (Swift-BAT trigger #224364; Morettim et al., GCN5442; Cummings et al. GCN 5443), triggered the Suzaku Wideband All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 22:50:24.295 (UT). The observed prompt emission exhibits a single-peaked lightcurve with a duration (T90) of 6.1 seconds. The fluence in 100 - 1000 keV was (1.0 +/- 0.1)X10^-6 erg/cm2. The 1-s peak flux was 5.6 +/- 0.2 photons/cm2/s in the same energy range. Preliminary result shows that the time-averaged spectrum is well-fitted by a power law with an exponential cutoff having the following parameters: alpha = 0.93 +- 0.31, E0 = 229 (+82, -53) keV, and Epeak = 248 +- 20 keV. All the quoted errors are at statistical 90% confidence level, not included in the systematic errors. Further detailed analyses are in progress.