TITLE: GCN CIRCULAR NUMBER: 18133 SUBJECT: IPN Triangulation of GRB 150811B DATE: 15/08/12 18:38:22 GMT FROM: Dmitry Svinkin at Ioffe Institute S. Golenetskii, R. Aptekar, V. Pal'shin, D. Frederiks, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, K. Hurley, on behalf of the IPN, V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa, and A. Goldstein, on behalf of the Fermi GBM team, and A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, report: The short-duration GRB 150811B has been detected by Fermi (GBM: Jenke, GCN Circ. 18130), Konus-Wind, and INTEGRAL (SPI-ACS), so far, at about 73334 s UT (20:22:14). We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 186.348 (12h 25m 23s) -14.105 (-14d 06' 20") Corners: 184.572 (12h 18m 17s) -16.337 (-16d 20' 12") 188.337 (12h 33m 21s) -12.037 (-12d 02' 14") 187.888 (12h 31m 33s) -11.720 (-11d 43' 10") 184.110 (12h 16m 26s) -16.010 (-16d 00' 36") --------------------------------------------- The error box area is 3.1 sq. deg, and its maximum dimension is 5.7 deg (the minimum one is 32.5 arcmin). The Sun distance was 52 deg. This box may be improved. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB150811_T73329/IPN/ The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular.