TITLE: GCN CIRCULAR NUMBER: 17502 SUBJECT: IPN Triangulation of GRB 150220A DATE: 15/02/24 15:29:11 GMT FROM: Dmitry Svinkin at Ioffe Institute K. Hurley and J. Goldsten, on behalf of the MESSENGER NS GRB team, I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin, on behalf of the HEND-Odyssey GRB team, S. Golenetskii, R. Aptekar, V. Pal'shin, D. Frederiks, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa, and A. Goldstein, on behalf of the Fermi GBM team, W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr, on behalf of the GRS-Odyssey GRB team, report: A long-duration GRB 150220A has been observed by Fermi (GBM trigger 446134898), Konus-Wind, Mars-Odyssey (HEND), and MESSENGER (GRNS), so far, at about 51696 s UT (14:21:36). We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 135.496 (09h 01m 59s) -1.597 ( -1d 35' 49") Corners: 135.673 (09h 02m 42s) -1.932 ( -1d 55' 54") 135.354 (09h 01m 25s) -2.064 ( -2d 03' 51") 135.322 (09h 01m 17s) -1.262 ( -1d 15' 42") 135.642 (09h 02m 34s) -1.124 ( -1d 07' 25") --------------------------------------------- The error box area is 943 sq. arcmin, and its maximum dimension is 59 arcmin (the minimum one is 19.6 arcmin). The Sun distance was 158 deg. This box may be improved. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB150220_T51704/IPN/ A Swift ToO observation has been scheduled (Evans, GCN Circ. 17501). The time history and spectrum will be given in forthcoming GCN Circulars.