TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4234 SUBJECT: IPN triangulation and Konus spectrum of the short/soft GRB051107 (large DATE: 05/11/09 18:49:19 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, and T. Cline on behalf of the Konus-Wind team, S. Barthelmy, J. Cummings, H. Krimm, N. Gehrels on behalf of the Swift team, A. Rau, A. von Kienlin, G. Lichti on behalf of the INTEGRAL SPI-ACS GRB team, K. Hurley on behalf of the Ulysses, HETE, Mars Odyssey teams report: A short soft GRB triggered the Konus-Wind instrument at T0=9044.551 s UT (02:30:44.551) on November 7. It was also observed by Swift-BAT, and INTEGRAL SPI-ACS. We have triangulated this burst to the 3sigma confidence error box: RA(2000) Dec(2000) ---------------------------------------- ERROR BOX CENTER: 94.016 -18.977 ERROR BOX CORNER 1: 102.953 -14.291 ERROR BOX CORNER 2: 85.388 -24.124 ERROR BOX CORNER 2: 83.432 -22.350 ERROR BOX CORNER 4: 101.222 -12.721 --------------------------------------- The area of the error box is ~40 sq. deg. The total burst duration is 1.75 sec. The K-W spectrum integrated over the most intense part of the GRB (from T0 to T0+0.256 sec) is well fitted (in the 20 - 500 keV range) by a power law with exponential cutoff model: dN/dE ~ E^(-alpha) * exp(-E/E0) with alpha = -0.51 (-1.07, +0.71) and E0 = 60 (-24, +38) keV (chi^2 = 15/27 dof). The peak energy Ep = 151 (-26, +34) keV. As observed by Konus-Wind the burst had a fluence 1.42(-0.79, +0.16)x10^-6 erg/cm2 and peak flux on 64-ms time scale 2.0(-1.2, +0.3)x10^-6 erg/cm2/sec (both in the 20 - 500 keV). All the quoted errors are at the 90% confidence level. The K-W light curve of this GRB and IPN triangulation map will be available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB051107_T09044/