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GCN Circular 36407

IPN triangulation of GRB 240504A
2024-05-07T16:29:24Z (11 days ago)
Dmitry Svinkin at Ioffe Institute <>
legacy email
A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin
on behalf of the HEND/Mars Odyssey team,

D. Svinkin, D. Frederiks, A. Ridnaia, A. Lysenko,
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,

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,


W. Boynton, C. Fellows, K. Harshman, H. Enos, R. Starr,
and A.S. Gardner on on behalf of the GRS-Odyssey GRB team,

The long-duration GRB 240504A
(Fermi-GBM detection: The Fermi GBM team, GCN 36387;
BALROG localization: Preis et al., GCN 36388;
Swift-BAT/GUANO detection: Ronchini et al., GCN 36401)
was detected by Fermi (GBM trigger 736492377), Konus-Wind,
INTEGRAL (SPI-ACS), Swift (BAT), and Mars-Odyssey (HEND)
at about 18773 s UT (05:12:53).
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
   64.767 (04h 19m 04s) -10.087 (-10d 05' 13")
   64.587 (04h 18m 21s) -11.558 (-11d 33' 29")
   64.659 (04h 18m 38s) -11.560 (-11d 33' 36")
   64.926 (04h 19m 42s)  -8.615 ( -8d 36' 53")
   64.854 (04h 19m 25s)  -8.613 ( -8d 36' 47")
The error box area is 756 sq. arcmin, and its maximum
dimension is 2.96 deg (the minimum one is 4.3 arcmin).
The Sun distance was 35 deg.

The IPN localization is consistent with, but reduces the area of,
the Fermi-GBM final and BALROG localizations.

This localization may be improved.

A triangulation map and HEALPix FITS file are posted at

The Konus-Wind time history and spectrum will be given
in a forthcoming GCN Circular.

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