Gamma-ray Burst 130812B

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN Circular #15094
  IPN Triangulation of GRB 130812B (long/bright)
  K. Hurley and J. Goldsten, on behalf of the MESSENGER NS GRB team,
  S. Golenetskii, R. Aptekar, V. Pal'shin, D. Frederiks, D. Svinkin, and T. Cline, on behalf of the Konus-Wind team,
  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, and
  S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf of the Swift-BAT team, report:
  The long-duration, soft spectrum, intense GRB 130812B has been observed by Konus-Wind, Suzaku (WAM), MESSENGER (GRNS), and Swift (BAT), so far, at about 39315 s UT (10:55:15). 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:
       7.671 (00h 30m 41s) -79.083 (-79d 04' 59")
    Corners:
       1.389 (00h 05m 33s) -80.672 (-80d 40' 18")
       3.895 (00h 15m 35s) -80.482 (-80d 28' 56")
      12.167 (00h 48m 40s) -77.409 (-77d 24' 32")
      10.472 (00h 41m 53s) -77.656 (-77d 39' 21")
    ---------------------------------------------
  

  The error box area is 2954 sq. arcmin, and its maximum dimension is 3.8 deg (the minimum one is 14 arcmin). The Sun distance was 112 deg.
  This box can be improved.
  The time history and spectrum will be given in a forthcoming GCN Circular.
  A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB130812_T39316/IPN/
• GCN Circular #15095
  S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline, on behalf of the Konus-Wind team, report:
  The long-duration =FB=F9=E0=E5-=FB=E7=F3=F1=E5=EA=E3=FC GRB 130812B (IPN triangulation: Hurley at al., GCN 15094) triggered Konus-Wind at T0=3D39316.109 s UT (10:55:16.109).
  The light curve shows multiple pulses from ~T0-0.5 s to ~T0+16s followed by a weak decaying emission during the next ~15 s.
  The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB130812_T39316/
  As observed by Konus-Wind, the burst had a fluence of (1.52 =B1 0.03)x10-5 erg/cm2, and a 64-ms peak flux, measured from T0+4.032s, of (3.5 =B1 0.3)x10-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
  The time-integrated spectrum (measured from T0 to T0+33.024 s) is best fit in the 20 keV - 15 MeV range by the cutoff power law with the following model parameters: the photon index alpha =3D -1.33 =B1 0.07, the peak energy Ep =3D 78 =B1 3 keV, chi2 =3D 90/98 dof.
  The time-averaged spectrum of the bright phase of the burst (measured from T0 to T0+16.640 s) is best fit in the 20 keV - 15 MeV range by the cutoff power law with the following model parameters: the photon index alpha =3D -1.04 =B1 0.07, the peak energy Ep =3D 90 =B1 2 keV, chi2 =3D 75/97 dof.
  All the quoted results are preliminary.
• GCN Circular #15096
  K. Hurley, I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin, on behalf of the HEND-Odyssey GRB team,
  S. Golenetskii, R. Aptekar, V. Pal'shin, D. Frederiks, D. Svinkin, and T. Cline, on behalf of the Konus-Wind team,
  J. Goldsten, on behalf of the MESSENGER NS GRB team,
  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, and
  S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf of the Swift-BAT team, report:
  GRB 130812B (Hurley et al., GCN 15094; Golenetskii et al., GCN 15095) was also observed by Odyssey. Using Odyssey data reduces the size of the previous error box by about a factor of eight:

    ---------------------------------------------
     RA(2000), deg                 Dec(2000), deg
    ---------------------------------------------
    Center:
       7.405 (00h 29m 37s) -79.178 (-79d 10' 39")
    Corners:
       8.180 (00h 32m 43s) -78.635 (-78d 38' 07")
       7.610 (00h 30m 26s) -79.359 (-79d 21' 32")
       6.536 (00h 26m 09s) -79.717 (-79d 43' 02")
       7.206 (00h 28m 49s) -78.996 (-78d 59' 47")
    ---------------------------------------------
  

  The area of this box is 349 sq. arcmin, and its maximum dimension is 1.1 deg (the minimum one is 8 arcmin).
  A new map has been posted at http://www.ioffe.ru/LEA/GRBs/GRB130812_T39316/IPN/
  Some improvement in this error box is possible.