Gamma-ray Burst 120816B

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN Circular #13675
  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.
• GCN Circular #13676
  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.