TITLE: GCN CIRCULAR NUMBER: 35751 SUBJECT: IPN triangulation of GRB 240209A DATE: 24/02/18 17:22:41 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru> D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia, and T. Cline on behalf of the Konus-Wind team, A. Goldstein, M. S. Briggs, C. Wilson-Hodge, and E. Burns on behalf of the Fermi GBM team, and S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu on behalf of the Swift-BAT team, report: The long-duration GRB 240209A (Fermi-GBM detection: The Fermi GBM team, GCN 35712; Malacaria et al., GCN 35729) was detected by Fermi (GBM trigger 729152364) and Konus-Wind, in the waiting mode, at about 22760 s UT (06:19:20). We have triangulated it to a Konus-GBM annulus centered at RA(2000)=119.672 deg (07h 58m 41s) Dec(2000)=+19.090 deg (+19d 05' 25"), whose radius is 66.074 +/- 14.729 deg (3 sigma). The annulus combined with the Fermi-GBM final position (GCN 35712; glg_healpix_all_bn240209263_v01) gives ~2019 sq. deg (3 sigma) localization region. The reported optical counterpart candidate GOTO24pw/AT2024cew (Belkin et al., GCN 35715) is outside the Konus-GBM annulus, implying that the optical transient is unrelated to the GRB. A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB240209_T22759/IPN View this GCN Circular online at https://gcn.nasa.gov/circulars/35751. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...