TITLE: GCN CIRCULAR NUMBER: 13755 SUBJECT: IPN Triangulation of GRB 120911B (long/bright) DATE: 12/09/12 20:35:44 GMT FROM: Valentin Pal'shin at Ioffe Inst K. Hurley on behalf of the Mars Odyssey and MESSENGER GRB teams, I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin, on behalf of the HEND-Odyssey 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, W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr, on behalf of the GRS-Odyssey GRB team, G. Di Cocco, F. Fuschino, M. Galli, C. Labanti, and M. Marisaldi, on behalf of the AGILE MCAL 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 long-duration, intense GRB 120911B has been observed by INTEGRAL (SPI-ACS), AGILE (MCAL), Konus-Wind, and Mars Odyssey (HEND), so far, at about 23175 s UT (06:26:15). We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 172.146 (11h 28m 35s) -37.696 (-37d 41' 46") Corners: 172.616 (11h 30m 28s) -38.705 (-38d 42' 20") 172.297 (11h 29m 11s) -38.543 (-38d 32' 34") 171.709 (11h 26m 50s) -36.675 (-36d 40' 31") 172.013 (11h 28m 03s) -36.848 (-36d 50' 53") --------------------------------------------- The error box area is 0.380 sq. deg, and its maximum dimension is 2.15 deg. This box can be improved. The time history and spectrum will be given in a forthcoming GCN Circular.