TITLE: GCN CIRCULAR NUMBER: 27595 SUBJECT: Improved IPN error box for GRB 200415A (consistent with the Sculptor Galaxy) DATE: 20/04/16 16:16:25 GMT FROM: Dmitry Svinkin at Ioffe Institute D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Ridnaia, and T. Cline on behalf of the Konus-Wind team, K. Hurley on behalf of the IPN, I. G. Mitrofanov, D. V. Golovin, A. S. Kozyrev, M. L. Litvak, and A. B. Sanin, on behalf of the HEND-Odyssey GRB team, A. Goldstein, M. S. Briggs, and C. Wilson-Hodge on behalf of the Fermi GBM 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, S. Barthelmy, J. Cummings, H. Krimm, and D. Palmer, 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: Using the Konus-Wind data we have triangulated this GRB to an improved, but still preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 11.874 (00h 47m 30s) -25.194 (-25d 11' 37") Corners: 11.760 (00h 47m 02s) -25.393 (-25d 23' 34") 12.022 (00h 48m 05s) -25.302 (-25d 18' 09") 11.987 (00h 47m 57s) -24.994 (-24d 59' 38") 11.726 (00h 46m 54s) -25.085 (-25d 05' 05") --------------------------------------------- The error box area is about 274 sq. arcmin, and its maximum dimension is 27 arcmin (the minimum one is 14.7 arcmin). The Sun distance was about 37 deg. This error box reduces the initial error box (Svinkin et al., GCN Circ. 27585). The Sculptor Galaxy (NGC 253) is mostly inside the box, strengthen the association the burst with the galaxy proposed in GCN 27585. We encourage an extensive search, both retrospective and follow-up, for an accompanying radio emission. This box may be further improved. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB200415_T31685/IPN/ The Swift (BAT) event data used for the IPN localization came from the GUANO system (https://www.swift.psu.edu/guano/). The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular.