TITLE:   GCN CIRCULAR
NUMBER:  32156
SUBJECT: IPN triangulation of GRB 220528A (short)
DATE:    22/06/01 09:13:49 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

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,

E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

and

S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu
on behalf of the Swift-BAT team, report:

The short-duration GRB 220528A
(Fermi-GBM detection: Fermi GBM Team, GCN Circ. 32147;
Mangan et al., GCN Circ. 32155;
Swift/BAT-GUANO detection: Raman et al., GCN Circ. 32148)
was detected by Fermi (GBM trigger 675411172),
INTEGRAL (SPI-ACS), Konus-Wind, and Swift (BAT)
at about 22367 s UT (06:12:47).
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:
   312.961 (20h 51m 51s) +18.856 (+18d 51' 22")
  Corners:
   315.010 (21h 00m 02s) +16.077 (+16d 04' 38")
   315.232 (21h 00m 56s) +16.369 (+16d 22' 08")
   310.761 (20h 43m 03s) +21.508 (+21d 30' 30")
   310.547 (20h 42m 11s) +21.215 (+21d 12' 55")
  ---------------------------------------------
The error box area is 2.3 sq. deg, and its maximum
dimension is 6.8 deg (the minimum one is 21 arcmin).
The Sun distance was 102 deg.

This box may be improved.

The IPN localization is consistent with, but reduces the area of, the
Fermi-GBM final localization (GCN Circ. 32147).

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB220528_T22370/IPN

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