GCN Circular 32104

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,

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

A long-duration GRB 220521B
has been detected by Konus-Wind, INTEGRAL (SPI-ACS),
and Mars-Odyssey (HEND), so far, at about 54210 s UT (15:03:30).

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
 ---------------------------------------------
  RA(2000), deg                 Dec(2000), deg
 ---------------------------------------------
 Center:
   55.464 (03h 41m 51s) +38.990 (+38d 59' 25")
 Corners:
   57.749 (03h 51m 00s) +34.608 (+34d 36' 29")
   52.895 (03h 31m 35s) +43.109 (+43d 06' 34")
   52.823 (03h 31m 18s) +43.047 (+43d 02' 49")
   57.684 (03h 50m 44s) +34.535 (+34d 32' 05")
 ---------------------------------------------
The error box area is 2520 sq. arcmin, and its maximum
dimension is 9.3 deg (the minimum one is 5 arcmin).
The Sun distance was 14 deg.

This box may be improved.

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB220521_T54209/IPN/

The time history and spectrum will be given in forthcoming GCN Circulars.