TITLE: GCN CIRCULAR NUMBER: 20091 SUBJECT: IPN Triangulation of GRB 161020B DATE: 16/10/22 11:22:49 GMT FROM: Anna Kozlova at Ioffe Institute K. Hurley, on behalf of the IPN, I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin, on behalf of the HEND-Odyssey GRB team, A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa, and A. Goldstein, 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, A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr, on behalf of the GRS-Odyssey GRB team, report: A long-duration GRB 161020B has been detected by Fermi (GBM), Konus-Wind, INTEGRAL (SPI-ACS), Mars-Odyssey (HEND), and Swift (BAT) at about 65597 s UT (18:13:17). 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: 63.105 (04h 12m 25s) -75.580 (-75d 34' 49") Corners: 68.180 (04h 32m 43s) -76.773 (-76d 46' 23") 68.921 (04h 35m 41s) -76.461 (-76d 27' 38") 58.787 (03h 55m 09s) -74.305 (-74d 18' 18") 57.959 (03h 51m 50s) -74.583 (-74d 35' 00") --------------------------------------------- The error box area is 4250 sq. arcmin, and its maximum dimension is 3.4 deg (the minimum one is 21 arcmin). The Sun distance was about 90 deg. This box may be improved. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB161020_T65597/IPN/ The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular.