GCN Circular 18852

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

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. 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, N. Gehrels, 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, extremely intense GRB 151229B has been detected by 
Konus-Wind, Swift (BAT), and INTEGRAL (SPI-ACS), so far, at about 77063 
s UT (21:24:23). The burst was outside the coded field of view of the 
BAT. The burst was Mars-occulted to Odyssey.

We have triangulated it to a preliminary, 3 sigma error box whose 
coordinates are:
  ---------------------------------------------
    RA(2000), deg                 Dec(2000), deg
   ---------------------------------------------
   Center:
     66.759 (04h 27m 02s)  -7.167 ( -7d 10' 00")
   Corners:
     71.595 (04h 46m 23s) -10.885 (-10d 53' 06")
     67.582 (04h 30m 20s)  -8.217 ( -8d 13' 00")
     62.910 (04h 11m 38s)  -3.557 ( -3d 33' 27")
     65.994 (04h 23m 59s)  -6.129 ( -6d 07' 46")
   ---------------------------------------------
The error box area is about 3 sq. deg,
and its maximum dimension is 11.3 deg
(the minimum one is 27 arcmin).
The Sun distance was 136 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB151229_T77056/IPN/

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