////////////////////////////////////////////////////////////////////////
TITLE:   GCN CIRCULAR
NUMBER:  13675
SUBJECT: IPN Triangulation of  GRB 120816B (short/exceptionally intense)
DATE:    12/08/18 14:32:17 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks,
D. Svinkin, and T. Cline on behalf of the Konus-Wind team,

K. Hurley on behalf of the IPN,

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

K. Yamaoka, M. Ohno, Y. Hanabata, Y. Fukazawa, T. Takahashi, M. Tashiro,
Y. Terada, T. Murakami, and K. Makishima on behalf of the Suzaku WAM
team, report:

The short-duration, hard, exceptionally intense GRB 120816B has been 
observed by Konus-Wind, INTEGRAL (SPI-ACS), Suzaku (WAM), and 
Swift(BAT), at about 86299 s UT (23:58:19). The burst was outside the 
coded field of view of the BAT.

We have triangulated the burst to a preliminary, 3 sigma error box whose
coordinates are:
   ---------------------------------------------
    RA(2000), deg                 Dec(2000), deg
   ---------------------------------------------
   Corners:
    341.155 (22h 44m 37s)  +2.156 ( +2d 09' 22")
    342.478 (22h 49m 55s)  -0.731 ( +0d 43' 51")
    334.205 (22h 16m 49s)  -5.388 ( -5d 23' 15")
    332.423 (22h 09m 42s)  -2.756 ( -2d 45' 20")
   ---------------------------------------------

The error box area is 10.030 sq. deg

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB120816_T86298/IPN/

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

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TITLE:   GCN CIRCULAR
NUMBER:  13676
SUBJECT: Konus-Wind observation of GRB 120816B
DATE:    12/08/18 14:52:56 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin,
P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf
of the Konus-Wind team, report:

The short-duration hard-spectrum exceptionally intense GRB 120816B
(IPN localization: Golenetskii at al., GCN 13675)
triggered Konus-Wind at T0=86298.852s UT (23:58:18.852)

The light curve shows a single multi-peaked pulse.
A total duration of the burst in is ~0.8 s (80-350 keV range)
with a hint of a soft extended tail lasting till ~T0+50 s.
The emission in the main phase of the burst is seen up to ~9 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB120816_T86298/

As observed by Konus-Wind the burst
had a fluence of 9.7(-0.5,+0.5)x10-5 erg/cm2,
and a 16-ms peak flux, measured from T0,
of 2.3(-0.2,+0.2)x10-4 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst (measured from T0 to T0+0.768 s)
is best fit in the 20 keV - 10 MeV range
by a power law with exponential cutoff model, for which
alpha = -0.61 (-0.04, +0.04),
and Ep = 2320(-130, +140) keV,
chi2 = 100/89 dof.

All the quoted results are preliminary.
All the quoted errors are at the 90% confidence level.