TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2448 SUBJECT: IPN triangulation of GRB031107 (two large error boxes) DATE: 03/11/14 19:52:28 GMT FROM: Kevin Hurley at UCBerkeley/SSL K. Hurley and T. Cline, on behalf of the Ulysses, Mars Odyssey, and KONUS GRB teams, E. Mazets and S. Golenetskii, on behalf of the Konus-Wind GRB team, I. Mitrofanov, S. Charyshnikov, V. Grinkov, A. Kozyrev, M. Litvak, and A. Sanin, 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, and D. M. Smith, R. P. Lin, J. McTiernan, R. Schwartz, C. Wigger, W. Hajdas, and A. Zehnder, on behalf of the RHESSI GRB team, report: Konus-Wind, Mars Odyssey - HEND, and RHESSI observed this ~25 s long burst at 66246 s. We have triangulated it to a preliminary annulus centered at RA, Decl (2000) = 342.257, -9.639 degrees, whose radius is 50.513 +/- 0.446 degrees (3 sigma). In addition, the Konus ecliptic latitude response limits the arrival direction to ecliptic latitudes between -50 and -20 degrees, that is, to those portions of the annulus between RA, Decl = 23, -46 and 34, -8 degrees, and 297, -41 and 355, -59 degrees. As this burst was not observed by Ulysses due to a high solar proton-induced background, only minor improvements to this localization are possible.