TITLE: GCN CIRCULAR NUMBER: 43192 SUBJECT: IPN triangulation of GRB 251220B (short) DATE: 25/12/22 21:25:26 GMT FROM: Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru> A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin on behalf of the HEND/Mars Odyssey team, A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin, 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, S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, A. Tohuvavohu, and J. DeLaunay 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 short-duration GRB 251220B (Fermi/GBM detection: The Fermi GBM team, GCN 43160; SVOM/GRM observation: Wang et al., GCN 43171) was detected by Fermi(GBM trigger 787966689), Konus-Wind, Swift(BAT), SVOM (GRM), and Mars-Odyssey (HEND), at about 85085 s UT (23:38:05). 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: 246.020 (16h 24m 05s) +44.550 (+44d 33' 00") Corners: 242.980 (16h 11m 55s) +43.398 (+43d 23' 51") 248.478 (16h 33m 55s) +45.405 (+45d 24' 19") 249.037 (16h 36m 09s) +45.540 (+45d 32' 24") 243.550 (16h 14m 12s) +43.587 (+43d 35' 13") --------------------------------------------- The error box area is 597 sq. arcmin, and its maximum dimension is 4.82 deg (the minimum one is 2.3 arcmin). The Sun distance was 71 deg. This localization may be improved. A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB251220_T85082/IPN/ The HEALPix triangulation map is the multi-order HEALPix in units of probability density. The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular. View this GCN Circular online at https://gcn.nasa.gov/circulars/43192. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...