{
  "bibcode": "2021GCN.29373....1R",
  "body": "A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks,\nM. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline\non behalf of the Konus-Wind team, report:\n\nTwo bright, short bursts from SGR 1935+2154\n(GECAM detection: Huang et al., GCN Circ. 29363\nIPN triangulation: Ridnaia et al., GCN Circ. 29365)\ntriggered Konus-Wind on 2021 January 27 at\n24616.685 s UT (06:50:16.685), hereafter burst #1; and\non 2021 January 29 at 25196.932 s UT (06:59:56.932), burst #2.\n\nThe burst light curves feature a sharp rise,\nfollowed by a gradual decay, and, finally,\na quick return of a count rate to the background level.\nAdditionally, the main pulse of burst #1 is preceded by\na weaker, partially overlapped sub-pulse.\nThe burst total durations are  ~100 ms (#1) and ~200 ms (#2).\nThe emission in both bursts is seen up to ~200 keV.\n\nAs measured by KW, the burst fluences and peak fluxes are as follows:\n------------------------------------------------------------------\n#  Date       T0(KW) s UT                   Fl*           PF**\n------------------------------------------------------------------\n1 20210127 24616.685 s UT(06:50:16.685)  0.91 +/-0.07  16.0 +/-3.2\n2 20210129 25196.932 s UT(06:59:56.932)  3.14 +/-0.11  27.5 +/-4.4\n------------------------------------------------------------------\n*  -  Fluence (20-500 keV) in units of 1e-6 erg/cm2\n\n** - Peak Flux (20-500 keV) on 2-ms time scale\n        in units of 1e-6 erg/cm2/s\n\nTime-averaged spectra of the bursts are well fit\nby a power law with exponential cutoff model:\ndN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)\nwith the following parameters:\n-------------------------------------------------------------\n#   Tbeg-Tend         alpha            Ep(keV)    chi2/dof\n-------------------------------------------------------------\n1   0 - 0.064    -0.21(-1.00,+1.20)    31(-10,+5)   13/11\n2   0 - 0.192    -0.33(-0.37,+0.40)    34(-3,+3)     14/20\n-------------------------------------------------------------\n\nThese spectral parameters are typical of a few dosen SGR 1935+2154\nshort bursts detected by KW previously (with the notable exception\nof the April 28 SGR/FRB event).\n\nThe Konus-Wind light curves of the bursts are available at\nhttp://www.ioffe.ru/LEA/SGRs/210127_T24616/\nhttp://www.ioffe.ru/LEA/SGRs/210129_T25196/\n\nAll the quoted errors are at the 90% confidence level.\nAll the quoted values are preliminary.",
  "circularId": 29373,
  "createdOn": 1611938355000,
  "email": "ridnaia@mail.ioffe.ru",
  "subject": "Konus-Wind detection of two bright bursts from SGR 1935+2154",
  "submitter": "Anna Ridnaia at Ioffe Institute  <ridnaia@mail.ioffe.ru>",
  "eventId": "SGR 1935+2154"
}