//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19784 SUBJECT: IPN Triangulation of GRB 160806A DATE: 16/08/09 12:59:49 GMT FROM: Anna Kozlova at Ioffe Institute 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. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa, and A. Goldstein, on behalf of the Fermi GBM team, S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf of the Swift-BAT team, A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr, on behalf of the GRS-Odyssey GRB team, report: A short-duration GRB 160806A has been detected by Fermi (GBM), Konus-Wind, INTEGRAL (SPI-ACS), Mars-Odyssey (HEND), and Swift (BAT) at about 50460 s UT (14:01:00). 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: 274.477 (18h 17m 54s) +10.607 (+10d 36' 25") Corners: 275.105 (18h 20m 25s) +10.412 (+10d 24' 42") 274.010 (18h 16m 02s) +11.481 (+11d 28' 52") 273.846 (18h 15m 23s) +10.795 (+10d 47' 42") 274.941 (18h 19m 46s) +9.712 ( +9d 42' 45") --------------------------------------------- The error box area is 3308 sq. arcmin, and its maximum dimension is 1.99 deg (the minimum one is 36 arcmin). The Sun distance was about 130 deg. This box may be improved. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB160806_T50460/IPN/ The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19785 SUBJECT: Konus-Wind observation of GRB 160806A DATE: 16/08/09 13:29:03 GMT FROM: Anna Kozlova at Ioffe Institute A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, report: The short-duration GRB 160806A (IPN triangulation: Hurley et al., GCN 19784) triggered Konus-Wind at T0=50460.639 s UT (14:01:00.639). The burst light curve shows a single pulse which starts at ~T0-0.5 s and has a total duration of ~1.0 s. The emission is seen up to ~8 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB160806_T50460/ As observed by Konus-Wind, the burst had a fluence of 1.16(-0.23,+0.49)x10^-6 erg/cm2, and a 16-ms peak flux, measured from T0-0.026 s, of 5.98(-3.46,+4.98)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The spectrum of the burst (measured from T0 to T0+0.256 s) is well fit in the 20 keV - 8 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.00 (-0.51,+0.80) and Ep = 219 (-76,+395) keV (chi2 = 43/33 dof). Fitting by a GRB (Band) model yields alpha = -0.63 (-0.65,+1.00), Ep = 171 (-59,+154) keV, and an upper limit on the high energy photon index: beta < -1.8 (chi2 = 40/32 dof) All the quoted errors are at the 90% confidence level. All the quoted values are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19786 SUBJECT: GRB 160806A: Fermi GBM observation DATE: 16/08/09 15:54:06 GMT FROM: Peter Veres at UAH P Veres (UAH) and C Meegan (UAH) report on behalf of the Fermi GBM Team: "At 14:00:58.42 UT on 6 August 2016, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 160806A (trigger 492184862 / 160806584) which was also detected by the Konus-Wind (Kozlova et al., GCN 19785) and located by the Interplanetary Network (Hurley et al., GCN 19784). The GBM on-ground location is consistent with the IPN position. The angle from the Fermi LAT boresight at the GBM trigger time is 112 degrees. This burst was also independently detected by INTEGRAL SPI-ACS. The GBM light curve consists of a single symmetric pulse with a duration (T90) of about 1.7 s (50-300 keV). The time-averaged spectrum from T0 to T0+2 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.58 +/- 0.14 and the cutoff energy, parameterized as Epeak, is 142 +/- 11 keV. The event fluence (10-1000 keV) in this time interval is (1.35 +/- 0.07)E-6 erg/cm^2. The 64 ms peak photon flux measured starting from T0+0.13 s in the 10-1000 keV band is 17.6 +/- 2.0 ph/s/cm^2. A Band function fits the spectrum equally well with Epeak= 122 +/- 15 keV, alpha = -0.41 +/- 0.20 and beta = -2.64 +/- 0.38. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."