TITLE: GCN CIRCULAR NUMBER: 32597 SUBJECT: IPN triangulation of GRB 220927A (long) DATE: 22/09/27 19:38:36 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, D. Svinkin, A. Lysenko, and T. Cline on behalf of the Konus-Wind team,
A. Goldstein, M. S. Briggs, and C. Wilson-Hodge on behalf of the Fermi GBM team,
E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB 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 220927A (Fermi-GBM detection: Fermi GBM Team, GCN 32594) has been detected by Fermi (GBM trigger 685949785), INTEGRAL (SPI-ACS), Konus-Wind, Mars-Odyssey (HEND), and Swift (BAT), so far, at about 20180 s UT (05:36:20). 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: 90.969 (06h 03m 52s) -22.946 (-22d 56' 45") Corners: 88.336 (05h 53m 21s) -23.483 (-23d 28' 59") 88.391 (05h 53m 34s) -23.818 (-23d 49' 04") 93.560 (06h 14m 14s) -22.267 (-22d 16' 00") 93.494 (06h 13m 59s) -21.929 (-21d 55' 45") --------------------------------------------- The error box area is 1.68 sq. deg, and its maximum dimension is 5.1 deg (the minimum one is 20 arcmin). The Sun distance was 90 deg.
This box may be improved.
The IPN localization is consistent with, but reduces the area of, the Fermi-GBM final localization (GCN 32594).
A triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB220927_T20180/IPN
The time history and spectrum will be given in forthcoming GCN Circulars.