TITLE: GCN CIRCULAR NUMBER: 15506 SUBJECT: IPN Triangulation of GRB 131118A DATE: 13/11/20 18:42:44 GMT FROM: Valentin Pal'shin at Ioffe Inst IPN Triangulation of GRB 131118A K. Hurley, and J. Goldsten, on behalf of the MESSENGER NS GRB team, S. Golenetskii, R. Aptekar, V. Pal'shin, D. Frederiks, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin, on behalf of the HEND-Odyssey GRB team, W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr, on behalf of the GRS-Odyssey GRB team, V. Connaughton, M. S. Briggs, C. Meegan, and V. Pelassa, on behalf of the Fermi GBM team, A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf of the Swift-BAT team, and K. Yamaoka, M. Ohno, Y. Hanabata, Y. Fukazawa, T. Takahashi, M. Tashiro, Y. Terada, T. Murakami, and K. Makishima on behalf of the Suzaku WAM team, report: The long-duration, intense GRB 131118A (Collazzi, GCN 15503) has been observed by Fermi (GBM: trigger 406508340), INTEGRAL (SPI-ACS), Swift (BAT), Suzaku (WAM), MESSENGER (GRNS), Mars Odyssey (HEND), and Konus-Wind, so far, at about 82737 s UT (22:58:57). The burst was outside the coded field of view of the BAT. We have triangulated it to a 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 349.863 (23h 19m 27s) -66.833 (-66d 49' 58") Corners: 350.415 (23h 21m 40s) -66.930 (-66d 55' 47") 349.800 (23h 19m 12s) -66.926 (-66d 55' 32") 349.313 (23h 17m 15s) -66.733 (-66d 44' 00") 349.924 (23h 19m 42s) -66.740 (-66d 44' 23") --------------------------------------------- The error box area is 162 sq. arcmin, and its maximum dimension is 29 arcmin (the minimum one is 12 arcmin). The Sun distance was 81.6 deg. The center of the GBM ground position (Collazzi, GCN 15503) is 2.6 deg from the center of the box. Some improvement in this triangulation is possible.