TITLE: GCN CIRCULAR NUMBER: 33484 SUBJECT: IPN triangulation of GRB 230309A DATE: 23/03/17 14:32:30 GMT FROM: Anna Ridnaia 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 team, J. Benkhoff on behalf of the BepiColombo team, A. Ridnaia, D. Frederiks, D. Svinkin, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, and S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu on behalf of the Swift-BAT team, report: The bright, long-duration GRB 230309A (AstroSat CZTI detection: Waratkar et al., GCN Circ. 33464) was detected by Konus-Wind, Swift (BAT), AstroSat (CZTI), and BepiColombo (MGNS), at about 45138 s UT (12:32:18). 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: 88.882 (05h 55m 32s) -62.196 (-62d 11' 45") Corners: 88.454 (05h 53m 49s) -63.663 (-63d 39' 48") 88.326 (05h 53m 18s) -63.585 (-63d 35' 05") 89.273 (05h 57m 06s) -60.728 (-60d 43' 40") 89.391 (05h 57m 34s) -60.806 (-60d 48' 20") --------------------------------------------- The error box area is 712 sq. arcmin, and its maximum dimension is 2.9 deg (the minimum one is 4 arcmin). The Sun distance was about 90 deg. This localization may be improved. A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB230309_T45138/IPN/ The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular.