GCN Circular 21998

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,

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Kozlova,
and T. Cline on behalf of the Konus-Wind 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, very bright GRB 171011B was detected
by Konus-Wind, INTEGRAL (SPI-ACS), Mars-Odyssey (HEND),
and Swift (BAT) at about 3935 s UT (01:05:35).
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:
   158.860 (10h 35m 26s)  +1.646 ( +1d 38' 46")
  Corners:
   159.793 (10h 39m 10s)  -2.035 ( -2d 02' 06")
   158.437 (10h 33m 45s)  +4.418 ( +4d 25' 05")
   158.940 (10h 35m 46s)  +6.060 ( +6d 03' 36")
   159.687 (10h 38m 45s)  -0.726 ( +0d 43' 33")
  ---------------------------------------------
The error box area is 2.646 sq. deg, and its maximum
dimension is 8.14 deg (the minimum one is 23.5 arcmin).
The Sun distance was 37 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB171011_T03931/IPN

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