TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4197 SUBJECT: IPN triangulation and Konus spectrum of the bright short/hard GRB051103 DATE: 05/11/05 19:37:26 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, N. Gehrels on behalf of the Swift team, K. Hurley and T. Cline, on behalf of the Ulysses, HETE, Mars Odyssey, and Konus GRB teams, I. Mitrofanov, A. Kozyrev, M. Litvak, A. Sanin, V. Tret'yakov and A. Parshukov, on behalf of the HEND-Odyssey GRB team, W. Boynton, C. Fellows, K. Harshman, C. Shinohara and R. Starr, on behalf of the GRS-Odyssey GRB team, D. M. Smith, R. P. Lin, J. McTiernan, R. Schwartz, C. Wigger, W. Hajdas, and A. Zehnder, on behalf of the RHESSI GRB team, J-L. Atteia, C. Graziani, and R. Vanderspek on behalf of the HETE team report: A very bright hard short GRB triggered the Konus-Wind instrument at T0=33943.785 s UT (09:25:43.785) on November 3. It was also observed by HETE-Fregate, Mars Odyssey (GRS and HEND), RHESSI, and Swift-BAT. We have triangulated this burst to the 3sigma confidence error box: RA(2000) Dec(2000) ---------------------------------------- ERROR BOX CENTER: 148.142 68.845 ERROR BOX CORNER 1: 148.563 69.189 ERROR BOX CORNER 2: 147.570 68.115 ERROR BOX CORNER 2: 147.731 68.499 ERROR BOX CORNER 4: 148.738 69.564 --------------------------------------- The area of the error box is 120 sq. arcmin. The error box is consistent with a source in M81. As observed by Konus-Wind the burst had a duration of 0.17 sec, fluence 2.34(-0.28, +0.31)10^-5 erg/cm2, and peak flux on 2ms time scale 1.89 (-0.35, +0.25)10^-3 erg/cm2/sec (both in 20 keV - 10 MeV range). The Epeak of the time-integrated spectrum is 1920 +/- 400 keV. Assuming this burst originated from a source in M81 (D = 4 Mpc), the isotrpoic energy release of this GRB is ~4.5x10^46 erg, which consistent with the energy release of 27 December giant flare from SGR 1806-20. The peak flux of this GRB is the largest ever observed for the Konus-Wind short GRBs. The burst light curve had a very steep rise ~4 msec and a decaying tail, similar to the initial pulses of SGR giant flares. All the quoted errors are at the 90% confidence level. The K-W light curve of this GRB and IPN triangulation map can be seen at http://www.ioffe.rssi.ru/LEA/GRBs/GRB051103_T33943/