TITLE: GCN CIRCULAR NUMBER: 23318 SUBJECT: IPN Triangulation of GRB 181008B (long) DATE: 18/10/10 18:44:25 GMT FROM: Dmitry Svinkin at Ioffe Institute D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Kozlova, and T. Cline on behalf of the Konus-Wind team, K. Hurley, on behalf of the IPN, A. Goldstein, M. S. Briggs, and C. Wilson-Hodge 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, and S. Barthelmy, J. Cummings, H. Krimm, and D. Palmer, on behalf of the Swift-BAT team, report: The long-duration GRB 181008B was detected by Fermi (GBM; trigger 560725347), Konus-Wind, Swift (BAT) and INTEGRAL (SPI-ACS), at about 75743 s UT (21:02:23). The burst was outside the coded field of view of the BAT. We have triangulated this GRB to a Konus-GBM annulus centered at RA(2000)=173.995 deg (11h 35m 59s) Dec(2000)=+4.777 deg (+4d 46' 38"), whose radius is 70.040 +/- 2.099 deg (3 sigma). The annulus combined with the Fermi-GBM final position 3 sigma error circle gives the following error box: --------------------------------- RA(2000), deg Dec(2000), deg --------------------------------- Center: 112.6582 -35.4039 Corners: 110.7043 -23.9434 105.1913 -20.9537 119.7336 -50.4173 121.7709 -44.6724 -------------------------------- The error box area is 116 sq. deg, and its maximum dimension is 31.6 deg (the minimum one is 4.2 deg). The Sun distance was about 62 deg. This box may be improved. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB180728_T76197/IPN This box was submitted for observation by the MASTER-Net robotic telescope network (http://observ.pereplet.ru; Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L). The time history and spectrum will be given in forthcoming GCN Circulars.