TITLE: GCN CIRCULAR NUMBER: 13778 SUBJECT: IPN Triangulation of long GRB 120916A DATE: 12/09/18 11:19:03 GMT FROM: Valentin Pal'shin at Ioffe Inst K. Hurley, and J. Goldsten, on behalf of the MESSENGER GRNS GRB team, S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, V. Connaughton, M. Briggs, and C. Meegan, on behalf of the Fermi GBM 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, moderately intense GRB 120916A (Fermi-LAT detection: Vianello, Ohno, and Connaughton, GCN 13777) has been observed by INTEGRAL (SPI-ACS), Konus-Wind, Fermi (GBM: trigger 369461323), MESSENGER (GRNS), Swift (BAT), and Suzaku (WAM), so far, at about 14866 s UT (04:07:46). The burst was outside the coded field of view of the BAT. We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 205.631 (13h 42m 31s) +36.700 (+36d 42' 00") Corners: 207.209 (13h 48m 50s) +35.578 (+35d 34' 41") 204.206 (13h 36m 49s) +37.722 (+37d 43' 20") 203.936 (13h 35m 45s) +37.776 (+37d 46' 33") 206.960 (13h 47m 50s) +35.646 (+35d 38' 44") --------------------------------------------- The error box area is 0.298 sq. deg, and its maximum dimension is 3.42 deg. This elongated box intersects the LAT error circle This box may be improved. A triangulation map showing the error box and the LAT error circle is posted at http://www.ioffe.ru/LEA/GRBs/GRB120916_T14864/IPN/ The time history and spectrum will be given in forthcoming GCN Circulars.