{
  "bibcode": "2009GCN.10083....1G",
  "body": "S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks,\nP. Oleynik, M. Ulanov, and D. Svinkin on behalf of\nthe Konus-Wind and Konus-RF teams, and\nT. Cline on behalf of the Konus-Wind team, report:\n\nThe long GRB 091024 (Swift-BAT trigger #373674: Marshall et al. GCN \n10062, Sakamoto et al. GCN 10072) was observed by Konus-Wind in the \nwaiting mode. The emission was detected in all three Konus-Wind energy \nbands: G1 (18-70  keV), G2 (70-360 keV) and G3 (360-1360 keV) with high \nS/N.\n\nThe burst light curve shows three pulses: the first pulse starts at \n~T0-10 s and has a duration of ~90 s, the second starts at ~T0+600 s and \nhas a duration of ~100 s, and the most intense third pulse starts at \nT0+840 s and has a duration of ~400 s; there is a low-level emission \nbetween the first and second pulses.\n\nThe most intense part of the third pulse was also detected by Konus-RF, \nwhile Coronas-F was exiting the SAA.\n\nThe GBM localizations suggest a common origin of these events (Bissaldi \n& Connaughton, GCN 10070). Both the K-W light curve and the K-W ecliptic \nlatitude response confirms this suggestion. So, we believe all these \npulses belong to the extremely long burst, GRB 091024, which has a total \nduration of ~1200 s. Hence, some optical observations of this burst were \nperformed during the most intense part of the prompt emission, but no \nbright optical flares have been reported.\n\nModeling of the K-W 3-channel spectra by\na power law with exponential cutoff model:\ndN/dE ~ E^(-alpha)*exp(-E*(2-alpha)/Ep)\nyields the following parameters:\n--------------------------------------------------\n       Tstart    Tstop       alpha      Ep (keV)\n--------------------------------------------------\nP1     -7          80   -1.1+/-0.2    500+/-160\nP2    606         703   -1.6+/-0.2    200+/-120\nP3    835        1194   -1.4+/-0.2    230+/-50\nTotal  -7        1194   -1.5+/-0.4    280+/-120\n--------------------------------------------------\nTstart, Tstop - seconds since the BAT trigger time\n\n\nAs observed by Konus-Wind, the burst had a fluence of (1.13 +/- \n0.12)x10^-4 erg/cm2 (in the 20 - 1300 keV energy range).\n\nAssuming z = 1.092 (Cucchiara, Fox & Tanvir, GCN 10065) and a standard \ncosmology model with H_0 = 70 km/s/Mpc, Omega_M=0.27, Omega_\\Lambda = \n0.7, the isotropic energy release E_iso ~3.2x10^53 erg.\n\nAll the quoted errors are estimated at the 1 sigma confidence level.\n\nThe K-W light curve of this burst is available at\nhttp://www.ioffe.rssi.ru/LEA/GRBs/GRB091024/",
  "circularId": 10083,
  "createdOn": 1256577528000,
  "email": "val@mail.ioffe.ru",
  "subject": "Konus-Wind and Konus-RF observations of GRB 091024",
  "submitter": "Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>",
  "eventId": "GRB 091024"
}