{
  "bibcode": "2014GCN.17108....1G",
  "body": "S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik,\nM. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, and T. Cline,\non behalf of the Konus-Wind team, report:\n\nThe long GRB 141121A (Swift-BAT trigger #619182: Lien et al., GCN 17075;\nKrimm et al., GCN 17083; MAXI/GSC detection: Honda et al., GCN 17077)\nwas detected by Konus-Wind in the waiting mode.\n\nThe burst light curve shows two emission episodes. The first started at \n~T0(BAT)-870 s with a duration of about 190 s and the second weaker \nepisode, which corresponds to the first BAT episode reported in GCN \n17075, started at ~T0(BAT)+50 s with a duration of about 270 s. The \nsecond BAT episode (from T0(BAT)+550 to T0(BAT)+675 s) is not seen in KW \ndata.\n\nThe first KW episode is likely related to GRB 141121A, since the KW \necliptic latitude response and IPN localization of the episode are \nconsistent with the position of GRB 141121A. The details of the IPN \nlocalization will be given in a forthcoming GCN circular. During the \nfirst episode the burst source was outside the BAT FoV (private \ncommunication with the BAT team).\n\nThe total burst duration is about 1200 s. Such a long duration and long \nperiods of low-level emission or quiescence is common for ultra-long GRB.\n\nThe KW light curve contains several data gaps. One of them (from \n~T0(BAT)-670 s to ~T0(BAT)-270 s) may bias the estimated duration of the \nfirst episode. The MAXI/GSC detection at ~T0(BAT)-356 s falls into this gap.\n\nAs observed by Konus-Wind, the first episode had a fluence of ~8x10^-6 \nerg/cm2 and a 2.944 s peak flux, measured from ~T0(BAT)-752 s, of \n~2x10^-7 erg/cm2/s (both estimated in the 20 keV - 10  MeV energy \nrange). The second episode had a fluence of ~6x10^-6 erg/cm2 estimated \nin the same energy range.\n\nAssuming the redshift z=1.47 (Perley et al., GCN 17081)\nand a standard cosmology model with H_0 = 70 km/s/Mpc,\nOmega_M = 0.27, and Omega_Lambda = 0.73,\nwe estimate the following rest-frame parameters:\nthe isotropic energy release E_iso is ~8x10^52 erg,\nthe peak luminosity L_iso is ~10^51 erg/s.\n\nThe K-W light curve of this burst is available at\nhttp://www.ioffe.ru/LEA/GRBs/GRB141121A/",
  "circularId": 17108,
  "createdOn": 1417185294000,
  "email": "svinkin@mail.ioffe.ru",
  "subject": "Konus-Wind observation of GRB 141121A",
  "submitter": "Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>",
  "eventId": "GRB 141121A"
}