TITLE:   GCN CIRCULAR
NUMBER:  32118
SUBJECT: IPN triangulation of GRB 220525A
DATE:    22/05/25 21:48:51 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 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, and C. Wilson-Hodge
on behalf of the Fermi GBM 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 220525A
(Fermi GBM detection: Fermi GBM Team, GCN Circ 32112;
BALROG localization: Kunzweiler et al., GCN Circ 32113)
has been detected by Fermi (GBM trigger 675130259), CALET (CGBM),
Konus-Wind, and Mars-Odyssey (HEND), so far,
at about 654 s UT (00:10:54).

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
    13.365 (00h 53m 28s) +16.396 (+16d 23' 46")
  Corners:
    17.561 (01h 10m 15s) +12.813 (+12d 48' 48")
     9.561 (00h 38m 15s) +18.778 (+18d 46' 42")
     9.753 (00h 39m 01s) +18.232 (+18d 13' 54")
    18.017 (01h 12m 04s) +11.551 (+11d 33' 04")
  ---------------------------------------------
The error box area is 4.2 sq. deg, and its maximum
dimension is 10.9 deg (the minimum one is 25 arcmin).
The Sun distance was 43 deg.

This box may be improved.

The IPN localization is consistent with, but reduces the area of, the
Fermi GBM Final Real-time position (GCN Circ. 32112) and BALROG
(GCN 32113) localizations.

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB220525_T00654/IPN/

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