TITLE: GCN CIRCULAR NUMBER: 19209 SUBJECT: IPN Triangulation of GRB 160310A DATE: 16/03/19 21:42:04 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, V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa, and A. Goldstein, on behalf of the Fermi GBM team, and S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf of the Swift-BAT team, report: The long-duration GRB 160310A was detected by Konus-Wind (Frederiks et al., GCN Circ. 19167), Fermi (LAT: Vianello et al., GCN Circ. 19158 and GBM: Toelge & Hui GCN Circ. 19167), and Swift (BAT), at about 1378 s UT (00:22:58). The burst was outside the coded field of view of the BAT. We have triangulated it to a Konus-GBM annulus centered at RA(2000)=178.455 deg (11h 53m 49s) Dec(2000)=-2.131 deg (-2d 07' 52"), whose radius is 76.571 +/- 0.876 deg (3 sigma) and to a Konus-BAT annulus centered at RA(2000)=178.592 deg (11h 54m 22s) Dec(2000)=-2.265 deg (-2d 15' 53"), whose radius is 76.187 +/- 1.716 deg (3 sigma). While the GBM position is in a good agreement with both the Konus-GBM and the Konus-BAT annuli, the LAT position reported in GCN 19158 is 2.9 deg (~10 sigma) from the Konus-GBM annulus center line. So we encourage further investigation of the LAT position. Using the method suggested by Pal'shin, et al., ApJS 207, 38, 2013 (sec. 4.2.1) and assuming a LAT error radius of 6 deg, we obtain the following joint LAT/IPN error box: -------------------------------- RA(2000), deg Dec(2000), deg -------------------------------- Center: 101.726 -7.1445 Corners: 100.850 -13.082 102.648 -13.076 102.726 -1.228 100.975 -1.191 --------------------------------- The error box area is 21 sq. deg, and its maximum dimension is 12 deg (the minimum one is 1.8 deg). A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB160310_T01391/IPN/