{
  "bibcode": "2015GCN.17357....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 GRB 150126A (MAXI/GSC detection: Takagi et al., GCN 17352; Fermi-GBM \ndetection: Stanbro, GCN 17353) triggered Konus-Wind at T0=75103.524 s UT \n(20:51:43.524).\n\nThe burst light curve shows several multi-peak emission episodes started \nat ~T0-800 s with a total duration of ~870 s; the last, most intense \npulse triggered Konus-Wind. There is a hint of low-level ongoing \nemission in the soft energy band G1 (~83-360 keV) out to about T0+230 s.\nThe K-W light curve and the K-W ecliptic latitude response confirm a \ncommon origin of all episodes. The position of the burst (Takagi et al., \nGCN 17352) was below the horizon for Fermi until ~20:50 UT (=T0(KW)-103 \ns), so it missed all emission episodes except the last one.\n\nThe Konus-Wind light curve of this GRB is available at\nhttp://www.ioffe.ru/LEA/GRBs/GRB150126_T75103/\n\nAs observed by Konus-Wind, the burst had a fluence of \n8.56(-0.88,+1.30)x10^-5 erg/cm2, and a 1024-ms peak flux, measured from \nT0+8.288 s, of 1.03(-0.23,+0.24)x10^-6 erg/cm2/s\n(both in the 20 keV - 10 MeV energy range).\n\nThe spectrum of the triggered part of the burst\n(measured from T0 to T0+24.832 s)\nis best fit in the 20 keV - 10 MeV range\nby a power law with exponential cutoff model:\ndN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)\nwith  alpha = -1.04(-0.28,+0.33)\nand Ep = 208(-36,+57) keV (chi2 = 74/60 dof).\nFitting by a GRB (Band) model yields the same alpha and Ep,\nand an upper limit on the high energy photon index: beta < 2.1\n(chi2 = 74/59 dof)\n\nAll the quoted errors are at the 90% confidence level.\nAll the quoted values are preliminary.\n\nThe burst duration, light curve shape, and energetics are similar to \nthose of other multi-episode ultra-long GRBs with durations of ~1-2 ks \n(e.g. GRB 020410A, GRB 080407A, GRB 091024A, GRB 110709B - see Virgili \net al. (2013), ApJ, 778:54 and references therein).\n\n[GCN OPS NOTE(28jan15): Per author's request, the \"A\" was added to the GRB name\nin the Subject-line.]",
  "circularId": 17357,
  "createdOn": 1422463507000,
  "email": "val@mail.ioffe.ru",
  "subject": "Konus-Wind observation of GRB 150126A reveals its ultra-long nature",
  "submitter": "Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>",
  "eventId": "GRB 150126A"
}