TITLE: GCN CIRCULAR NUMBER: 31510 SUBJECT: IPN triangulation of GRB 211226A DATE: 22/01/21 13:31:08 GMT FROM: Dmitry Svinkin at Ioffe Institute A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin on behalf of the MGNS/BepiColombo and HEND/Mars Odyssey teams, J. Benkhoff on behalf of the BepiColombo team, D. Svinkin, D. Frederiks, A. Ridnaia, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu on behalf of the Swift-BAT team, and W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr, on behalf of the GRS-Odyssey GRB team, report: The long-duration GRB 211226A (AGILE/MCAL detection: Ursi et al., GCN Circ. 31309; Swift/BAT-GUANO detection: Tohuvavohu et al., GCN Circ. 31313) was detected by AGILE (MCAL), Swift (BAT), Konus-Wind, INTEGRAL (SPI-ACS), Mars-Odyssey (HEND), and BepiColombo (MGNS) at about 19540 s UT (05:25:40). 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: 241.834 (16h 07m 20s) -31.406 (-31d 24' 20") Corners: 242.222 (16h 08m 53s) -31.675 (-31d 40' 30") 241.641 (16h 06m 34s) -31.445 (-31d 26' 41") 241.450 (16h 05m 48s) -31.118 (-31d 07' 03") 242.025 (16h 08m 06s) -31.364 (-31d 21' 50") --------------------------------------------- The error box area is 424 sq. arcmin, and its maximum dimension is 52 arcmin (the minimum one is 12 arcmin). The Sun distance was 30 deg. This box may be improved. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB211226_T19539/IPN