TITLE:   GCN CIRCULAR
NUMBER:  21753
SUBJECT: IPN Triangulation of GRB 170826B
DATE:    17/08/29 16:44:47 GMT
FROM:    Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>

K. Hurley, on behalf of the IPN,

I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin,
on behalf of the HEND-Odyssey GRB team,

A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin,
and T. Cline on behalf of the Konus-Wind team,

V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa,
and A. Goldstein, on behalf of the Fermi GBM team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

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

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


The long-duration GRB 170826B (Poolakkil et al., GCN 21717) was detected
by Fermi (GBM trigger 525469141), Konus-Wind, INTEGRAL (SPI-ACS),
Insight (HXMT, Li et al., GCN 21739), Mars-Odyssey (HEND),
and Swift (BAT) at about 70736 s UT (19:38:56).
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:
   331.259 (22h 05m 02s) -33.916 (-33d 54' 58")
  Corners:
   329.379 (21h 57m 31s) -34.070 (-34d 04' 13")
   329.998 (21h 59m 59s) -34.318 (-34d 19' 05")
   333.019 (22h 12m 04s) -33.643 (-33d 38' 34")
   332.435 (22h 09m 44s) -33.458 (-33d 27' 30")
  ---------------------------------------------
The error box area is 3108 sq. arcmin, and its maximum
dimension is 3.1 deg (the minimum one is 20 arcmin).
The Sun distance was 155 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB170826_T70742/IPN

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