TITLE: GCN CIRCULAR NUMBER: 39013 SUBJECT: Improved IPN triangulation of GRB 250107C DATE: 25/01/22 15:22:14 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru> A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin on behalf of the MGNS/BepiColombo and the HEND/Mars-Odyssey teams, J. Benkhoff on behalf of the BepiColombo team, D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia, and T. Cline on behalf of the Konus-Wind team, Y. Zhang, C. Wang, S. Xiong, J. Wei, and B. Cordier on behalf of the SVOM-GRM team, A. Goldstein, M. S. Briggs, C. Wilson-Hodge, and E. Burns on behalf of the Fermi GBM 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, R. Starr, and A.S. Gardner on on behalf of the GRS-Odyssey GRB team, report: The long-duration GRB 250107C (SVOM-GRM and GECAM-B detections: Xue et al., GCN 38870; initial IPN triangulation: Svinkin et al., GCN 38879; Konus-Wind detection: Frederiks et al., GCN 38895; CALET-GBM detection: Yoshida et al., GCN 38896) was detected by Konus-Wind, SVOM (GRM), GECAM-B, CALET (GBM), and BepiColombo (MGNS) at about 67936 s UT (18:52:16). We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: ------------------------------- RA(2000), deg Dec(2000), deg ------------------------------- Corners: 348.940 +19.143 344.400 +27.679 344.615 +27.357 348.961 +19.155 ------------------------------- The error box area is 825 sq. arcmin, and its maximum dimension is 10.5 deg (the minimum one is 1.4 arcmin). The Sun distance was 70 deg. This localization may be improved. A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB250107_T67934/IPN/ The HEALPix triangulation map is the multi-order HEALPix in units of probability density. View this GCN Circular online at https://gcn.nasa.gov/circulars/39013. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...