//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16184 SUBJECT: IPN Triangulation of GRB 140428B (short/hard) DATE: 14/04/29 19:10:53 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R. Aptekar, V. Pal'shin, D. Frederiks, D. Svinkin, and T. Cline, on behalf of the Konus-Wind team, K. Hurley, on behalf of the Interplanetary Network, I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin, on behalf of the HEND-Odyssey GRB team, W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr, on behalf of the GRS-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, and V. Connaughton, M. S. Briggs, C. Meegan, and V. Pelassa, on behalf of the Fermi GBM team, report: The short-duration, hard spectrum GRB 140428B has been observed by Fermi (GBM: trigger 420414281), INTEGRAL (SPI-ACS), Konus-Wind, and Mars Odyssey (HEND), so far, at about 78278 s UT (21:44:38). We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 2.006 (00h 08m 01s) +68.172 (+68d 10' 20") Corners: 6.132 (00h 24m 32s) +68.636 (+68d 38' 09") 2.619 (00h 10m 29s) +68.455 (+68d 27' 18") 358.176 (23h 52m 42s) +67.601 (+67d 36' 04") 1.415 (00h 05m 40s) +67.887 (+67d 53' 13") --------------------------------------------- The error box area is 0.608 sq. deg, and its maximum dimension is 3.14 deg (the minimum one is 18 arcmin). This box may be improved. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB140428_T78275/IPN/ The time history and spectrum will be given in a forthcoming GCN Circular. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16188 SUBJECT: Konus-Wind observation of GRB 140428B DATE: 14/04/30 15:18:38 GMT FROM: Valentin Pal'shin at Ioffe Inst 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 short-duration GRB 140428B (IPN triangulation: Golenetskii et al., GCN 16184) triggered Konus-Wind at T0=78275.456 s UT (21:44:35.456). The burst light curve shows a single pulse with a total duration of ~0.15 s. As observed by Konus-Wind, the burst had a fluence of 9.23(-0.95,+0.88)x10^-7 erg/cm2, and a 16-ms peak flux, measured from T0-0.014 s, of (1.43 +/- 0.38)x10^-5 erg/cm2/s (both in the 20 keV - 1.2 MeV energy range). Modeling the K-W 3-channel time-integrated spectrum (from T0-0.064 s to T0+0.80 s) by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) yields alpha = -0.75(-0.24, +0.26), and Ep = 1050(-343,+1750) keV All the quoted errors are estimated at the 1 sigma confidence level. All the quoted results are preliminary. The K-W light curve of this burst is available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB140428_T78275/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16189 SUBJECT: GRB 140428B: Fermi GBM observation DATE: 14/04/30 17:52:37 GMT FROM: George A. Younes at USRA/NASA/MSFC George Younes (USRA/MSFC) report on behalf of the Fermi GBM Team: "At 21:44:38.60 UT on 28 April 2014, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 140428B (trigger 420414281 / 140428906, IPN triangulation: Golenetskii et al., GCN 16184). The angle from the Fermi LAT boresight is 111 degrees. This burst also triggered Konus-Wind (Pal'shin et al. GCN #16188). The GBM light curve consists of a single pulse with a duration (T90) of about 0.5 s (50-300 keV). The time-averaged spectrum from T0-0.32 s to T0+19 s is well fit by a power law function with an exponential high-energy cutoff. The power law index is -0.6 +/- 0.2 and the cutoff energy, parameterized as Epeak, is 410 (-80, +134) keV. The event fluence (10-1000 keV) in this time interval is (9.0 +/- 1.0)E-07 erg/cm^2. The 0.064-sec peak photon flux measured starting from T0-0.064 s in the 10-1000 keV band is 17 +/- 2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."